diff --git a/@noctaCrdt/LinkedList.ts b/@noctaCrdt/LinkedList.ts
index de84c19a..759c07a0 100644
--- a/@noctaCrdt/LinkedList.ts
+++ b/@noctaCrdt/LinkedList.ts
@@ -300,6 +300,8 @@ export class BlockLinkedList extends LinkedList<Block> {
     if (targetNode.prev) {
       const prevNode = this.getNode(targetNode.prev);
       if (prevNode) prevNode.next = targetNode.next;
+    } else {
+      this.head = targetNode.next;
     }
 
     if (targetNode.next) {
diff --git a/client/src/features/editor/Editor.tsx b/client/src/features/editor/Editor.tsx
index 6951cbf2..962a0e14 100644
--- a/client/src/features/editor/Editor.tsx
+++ b/client/src/features/editor/Editor.tsx
@@ -1,4 +1,4 @@
-import { DndContext } from "@dnd-kit/core";
+import { DndContext, DragEndEvent } from "@dnd-kit/core";
 import { SortableContext, verticalListSortingStrategy } from "@dnd-kit/sortable";
 import { EditorCRDT } from "@noctaCrdt/Crdt";
 import { BlockLinkedList } from "@noctaCrdt/LinkedList";
@@ -48,6 +48,7 @@ export const Editor = ({ onTitleChange, pageId, pageTitle, serializedEditorData
   const [displayTitle, setDisplayTitle] = useState(
     pageTitle === "새로운 페이지" || pageTitle === "" ? "" : pageTitle,
   );
+  const [dragBlockList, setDragBlockList] = useState<string[]>([]);
 
   const editorCRDTInstance = useMemo(() => {
     let newEditorCRDT;
@@ -80,7 +81,7 @@ export const Editor = ({ onTitleChange, pageId, pageTitle, serializedEditorData
     addNewBlock,
   } = useEditorOperation({ editorCRDT, pageId, setEditorState });
 
-  const { sensors, handleDragEnd } = useBlockDragAndDrop({
+  const { sensors, handleDragEnd, handleDragStart } = useBlockDragAndDrop({
     editorCRDT: editorCRDT.current,
     editorState,
     setEditorState,
@@ -272,7 +273,15 @@ export const Editor = ({ onTitleChange, pageId, pageTitle, serializedEditorData
           className={editorTitle}
         />
         <div style={{ height: "36px" }}></div>
-        <DndContext sensors={sensors} onDragEnd={handleDragEnd}>
+        <DndContext
+          onDragEnd={(event: DragEndEvent) => {
+            handleDragEnd(event, dragBlockList, () => setDragBlockList([]));
+          }}
+          onDragStart={(event) => {
+            handleDragStart(event, setDragBlockList);
+          }}
+          sensors={sensors}
+        >
           <SortableContext
             items={editorState.linkedList
               .spread()
@@ -298,6 +307,7 @@ export const Editor = ({ onTitleChange, pageId, pageTitle, serializedEditorData
                 onTextStyleUpdate={onTextStyleUpdate}
                 onTextColorUpdate={onTextColorUpdate}
                 onTextBackgroundColorUpdate={onTextBackgroundColorUpdate}
+                dragBlockList={dragBlockList}
               />
             ))}
           </SortableContext>
diff --git a/client/src/features/editor/components/IconBlock/IconBlock.style.ts b/client/src/features/editor/components/IconBlock/IconBlock.style.ts
index 45076f63..be2c8720 100644
--- a/client/src/features/editor/components/IconBlock/IconBlock.style.ts
+++ b/client/src/features/editor/components/IconBlock/IconBlock.style.ts
@@ -20,7 +20,7 @@ export const iconStyle = cva({
   variants: {
     type: {
       ul: {
-        fontSize: "20px", // bullet point size
+        fontSize: "6px", // bullet point size
       },
       ol: {
         paddingRight: "4px",
diff --git a/client/src/features/editor/components/IconBlock/IconBlock.tsx b/client/src/features/editor/components/IconBlock/IconBlock.tsx
index 5c369560..70c466db 100644
--- a/client/src/features/editor/components/IconBlock/IconBlock.tsx
+++ b/client/src/features/editor/components/IconBlock/IconBlock.tsx
@@ -4,13 +4,20 @@ import { iconContainerStyle, iconStyle } from "./IconBlock.style";
 interface IconBlockProps {
   type: ElementType;
   index: number | undefined;
+  indent?: number;
 }
 
-export const IconBlock = ({ type, index = 1 }: IconBlockProps) => {
+export const IconBlock = ({ type, index = 1, indent = 0 }: IconBlockProps) => {
   const getIcon = () => {
     switch (type) {
       case "ul":
-        return <span className={iconStyle({ type: "ul" })}>•</span>;
+        return (
+          <span className={iconStyle({ type: "ul" })}>
+            {indent === 0 && "●"}
+            {indent === 1 && "○"}
+            {indent === 2 && "■"}
+          </span>
+        );
       case "ol":
         return <span className={iconStyle({ type: "ol" })}>{`${index}.`}</span>;
       case "checkbox":
diff --git a/client/src/features/editor/components/block/Block.style.ts b/client/src/features/editor/components/block/Block.style.ts
index bf73bd7f..89e9dc3e 100644
--- a/client/src/features/editor/components/block/Block.style.ts
+++ b/client/src/features/editor/components/block/Block.style.ts
@@ -142,3 +142,30 @@ export const textContainerStyle = cva({
     type: "p",
   },
 });
+
+export const dropIndicatorStyle = cva({
+  base: {
+    zIndex: "10",
+    position: "absolute",
+    height: "2px",
+  },
+  variants: {
+    indent: {
+      first: {
+        left: "0",
+        width: "100%",
+        backgroundColor: "#ADADFF",
+      },
+      second: {
+        left: "10px",
+        width: "calc(100% - 10px)",
+        backgroundColor: "#9B9BFF ",
+      },
+      third: {
+        left: "20px",
+        width: "calc(100% - 20px)",
+        backgroundColor: "#8989FF",
+      },
+    },
+  },
+});
diff --git a/client/src/features/editor/components/block/Block.tsx b/client/src/features/editor/components/block/Block.tsx
index c3bea61d..4e165c18 100644
--- a/client/src/features/editor/components/block/Block.tsx
+++ b/client/src/features/editor/components/block/Block.tsx
@@ -1,5 +1,4 @@
 import { useSortable } from "@dnd-kit/sortable";
-import { CSS } from "@dnd-kit/utilities";
 import {
   AnimationType,
   ElementType,
@@ -20,11 +19,17 @@ import { MenuBlock } from "../MenuBlock/MenuBlock";
 import { TextOptionModal } from "../TextOptionModal/TextOptionModal";
 import { TypeOptionModal } from "../TypeOptionModal/TypeOptionModal";
 import { blockAnimation } from "./Block.animation";
-import { textContainerStyle, blockContainerStyle, contentWrapperStyle } from "./Block.style";
+import {
+  textContainerStyle,
+  blockContainerStyle,
+  contentWrapperStyle,
+  dropIndicatorStyle,
+} from "./Block.style";
 
 interface BlockProps {
   id: string;
   block: CRDTBlock;
+  dragBlockList: string[];
   isActive: boolean;
   onInput: (e: React.FormEvent<HTMLDivElement>, block: CRDTBlock) => void;
   onCompositionEnd: (e: React.CompositionEvent<HTMLDivElement>, block: CRDTBlock) => void;
@@ -64,6 +69,7 @@ export const Block: React.FC<BlockProps> = memo(
   ({
     id,
     block,
+    dragBlockList,
     isActive,
     onInput,
     onCompositionEnd,
@@ -83,13 +89,23 @@ export const Block: React.FC<BlockProps> = memo(
     const { isOpen, openModal, closeModal } = useModal();
     const [selectedNodes, setSelectedNodes] = useState<Array<Char> | null>(null);
     const { isAnimationStart } = useBlockAnimation(blockRef);
-    const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({
-      id,
-      data: {
-        type: "block",
-        block,
-      },
-    });
+    const { attributes, listeners, setNodeRef, isDragging, isOver, activeIndex, overIndex, data } =
+      useSortable({
+        id,
+        data: {
+          id,
+          type: "block",
+          block,
+        },
+      });
+
+    // 현재 드래그 중인 부모 블록의 indent 확인
+    const isChildOfDragging = dragBlockList.some((item) => item === data.id);
+
+    // NOTE 드롭 인디케이터 위치 계산
+    // 현재 over 중인 블럭 위치 + 위/아래로 모두 인디케이터 표시 + 부모요소는 자식요소 내부로는 이동하지 못함
+    const showTopIndicator = isOver && !isChildOfDragging && activeIndex >= overIndex;
+    const showBottomIndicator = isOver && !isChildOfDragging && activeIndex < overIndex;
 
     const [slashModalOpen, setSlashModalOpen] = useState(false);
     const [slashModalPosition, setSlashModalPosition] = useState({ top: 0, left: 0 });
@@ -214,6 +230,14 @@ export const Block: React.FC<BlockProps> = memo(
       }
     };
 
+    const Indicator = () => (
+      <div
+        className={dropIndicatorStyle({
+          indent: block.indent === 0 ? "first" : block.indent === 1 ? "second" : "third",
+        })}
+      />
+    );
+
     useEffect(() => {
       if (blockRef.current) {
         setInnerHTML({ element: blockRef.current, block });
@@ -223,66 +247,66 @@ export const Block: React.FC<BlockProps> = memo(
     return (
       // TODO: eslint 규칙을 수정해야 할까?
       // TODO: ol일때 index 순서 처리
-      <motion.div
-        ref={setNodeRef}
-        className={blockContainerStyle({ isActive })}
-        style={{
-          transform: CSS.Transform.toString(transform),
-          transition,
-          opacity: isDragging ? 0.5 : undefined,
-        }}
-        initial={blockAnimation[block.animation || "none"].initial}
-        animate={isAnimationStart && blockAnimation[block.animation || "none"].animate}
-        data-group
-      >
+      <div style={{ position: "relative" }}>
+        {showTopIndicator && <Indicator />}
         <motion.div
-          className={contentWrapperStyle()}
-          style={{ paddingLeft: `${block.indent * 12}px` }}
+          ref={setNodeRef}
+          className={blockContainerStyle({ isActive })}
+          style={{ opacity: isDragging || isChildOfDragging ? 0.3 : undefined }}
+          initial={blockAnimation[block.animation || "none"].initial}
+          animate={isAnimationStart && blockAnimation[block.animation || "none"].animate}
+          data-group
         >
-          <MenuBlock
-            attributes={attributes}
-            listeners={listeners}
-            onAnimationSelect={handleAnimationSelect}
-            onTypeSelect={handleTypeSelect}
-            onCopySelect={handleCopySelect}
-            onDeleteSelect={handleDeleteSelect}
+          <motion.div
+            className={contentWrapperStyle()}
+            style={{ paddingLeft: `${block.indent * 12}px` }}
+          >
+            <MenuBlock
+              attributes={attributes}
+              listeners={listeners}
+              onAnimationSelect={handleAnimationSelect}
+              onTypeSelect={handleTypeSelect}
+              onCopySelect={handleCopySelect}
+              onDeleteSelect={handleDeleteSelect}
+            />
+            <IconBlock type={block.type} index={block.listIndex} indent={block.indent} />
+            <div
+              ref={blockRef}
+              onKeyDown={(e) => onKeyDown(e, blockRef.current, block)}
+              onInput={handleInput}
+              onClick={(e) => onClick(block.id, e)}
+              onCopy={(e) => onCopy(e, blockRef.current, block)}
+              onPaste={(e) => onPaste(e, blockRef.current, block)}
+              onMouseUp={handleMouseUp}
+              onCompositionEnd={(e) => onCompositionEnd(e, block)}
+              contentEditable={block.type !== "hr"}
+              spellCheck={false}
+              suppressContentEditableWarning
+              className={textContainerStyle({
+                type: block.type,
+              })}
+            />
+          </motion.div>
+          <TextOptionModal
+            selectedNodes={selectedNodes}
+            isOpen={isOpen}
+            onClose={closeModal}
+            onBoldSelect={() => handleStyleSelect("bold")}
+            onItalicSelect={() => handleStyleSelect("italic")}
+            onUnderlineSelect={() => handleStyleSelect("underline")}
+            onStrikeSelect={() => handleStyleSelect("strikethrough")}
+            onTextColorSelect={handleTextColorSelect}
+            onTextBackgroundColorSelect={handleTextBackgroundColorSelect}
           />
-          <IconBlock type={block.type} index={block.listIndex} />
-          <div
-            ref={blockRef}
-            onKeyDown={(e) => onKeyDown(e, blockRef.current, block)}
-            onInput={handleInput}
-            onClick={(e) => onClick(block.id, e)}
-            onCopy={(e) => onCopy(e, blockRef.current, block)}
-            onPaste={(e) => onPaste(e, blockRef.current, block)}
-            onMouseUp={handleMouseUp}
-            onCompositionEnd={(e) => onCompositionEnd(e, block)}
-            contentEditable={block.type !== "hr"}
-            spellCheck={false}
-            suppressContentEditableWarning
-            className={textContainerStyle({
-              type: block.type,
-            })}
+          <TypeOptionModal
+            isOpen={slashModalOpen}
+            onClose={() => setSlashModalOpen(false)}
+            onTypeSelect={(type) => handleTypeSelect(type)}
+            position={slashModalPosition}
           />
         </motion.div>
-        <TextOptionModal
-          selectedNodes={selectedNodes}
-          isOpen={isOpen}
-          onClose={closeModal}
-          onBoldSelect={() => handleStyleSelect("bold")}
-          onItalicSelect={() => handleStyleSelect("italic")}
-          onUnderlineSelect={() => handleStyleSelect("underline")}
-          onStrikeSelect={() => handleStyleSelect("strikethrough")}
-          onTextColorSelect={handleTextColorSelect}
-          onTextBackgroundColorSelect={handleTextBackgroundColorSelect}
-        />
-        <TypeOptionModal
-          isOpen={slashModalOpen}
-          onClose={() => setSlashModalOpen(false)}
-          onTypeSelect={(type) => handleTypeSelect(type)}
-          position={slashModalPosition}
-        />
-      </motion.div>
+        {showBottomIndicator && <Indicator />}
+      </div>
     );
   },
 );
diff --git a/client/src/features/editor/hooks/useBlockDragAndDrop.ts b/client/src/features/editor/hooks/useBlockDragAndDrop.ts
index ae880a5b..db65a6c7 100644
--- a/client/src/features/editor/hooks/useBlockDragAndDrop.ts
+++ b/client/src/features/editor/hooks/useBlockDragAndDrop.ts
@@ -1,8 +1,12 @@
-// hooks/useBlockDragAndDrop.ts
-import { DragEndEvent, PointerSensor, useSensor, useSensors } from "@dnd-kit/core";
+import { DragEndEvent, DragStartEvent, PointerSensor, useSensor, useSensors } from "@dnd-kit/core";
 import { EditorCRDT } from "@noctaCrdt/Crdt";
+import { Block } from "@noctaCrdt/Node";
 import { useSocketStore } from "@src/stores/useSocketStore.ts";
 import { EditorStateProps } from "../Editor";
+import {
+  RemoteBlockReorderOperation,
+  RemoteBlockUpdateOperation,
+} from "node_modules/@noctaCrdt/Interfaces";
 
 interface UseBlockDragAndDropProps {
   editorCRDT: EditorCRDT;
@@ -25,12 +29,98 @@ export const useBlockDragAndDrop = ({
     }),
   );
 
-  const { sendBlockReorderOperation } = useSocketStore();
+  const { sendBlockReorderOperation, sendBlockUpdateOperation } = useSocketStore();
+
+  const getBlocksToMove = (nodes: Block[], parentIndex: number, parentIndent: number): Block[] => {
+    const blocksToMove = [];
+    let i = parentIndex + 1;
+
+    // 자식 블록들 찾기
+    while (i < nodes.length && nodes[i].indent > parentIndent) {
+      blocksToMove.push(nodes[i]);
+      i += 1;
+    }
+
+    return blocksToMove;
+  };
+
+  const reorderBlocksWithChildren = (
+    nodes: Block[],
+    targetNode: Block,
+    beforeNode: Block | null,
+    afterNode: Block | null,
+  ) => {
+    const operations = [];
+    const targetIndex = nodes.indexOf(targetNode);
+    const childBlocks = getBlocksToMove(nodes, targetIndex, targetNode.indent);
+
+    // 이동할 위치의 부모 블록 indent 찾기
+    let newIndent = 0;
+    if (beforeNode) {
+      // 앞 블록이 있는 경우, 그 블록의 indent를 기준으로
+      newIndent = beforeNode.indent;
+    } else if (afterNode) {
+      // 뒤 블록이 있는 경우, 그 블록의 indent를 기준으로
+      newIndent = afterNode.indent;
+    }
+
+    // indent 변화량 계산 -> 추후 자식 블록들에 indentDiff만큼 적용
+    const indentDiff = newIndent - targetNode.indent;
+    // 타겟 블록 업데이트
+    targetNode.indent = newIndent;
+
+    // 타겟 블록의 reorder 연산 처리
+    const targetReorderOp = editorCRDT.localReorder({
+      targetId: targetNode.id,
+      beforeId: beforeNode?.id || null,
+      afterId: afterNode?.id || null,
+      pageId,
+    });
+    operations.push({ type: "reorder", operation: targetReorderOp });
+
+    // Update 연산 (indent 갱신)
+    const targetUpdateOp = editorCRDT.localUpdate(targetNode, pageId);
+    operations.push({ type: "update", operation: targetUpdateOp });
+
+    // 자식 블록들 처리
+    let prevBlock = targetNode;
+    childBlocks.forEach((childBlock, index) => {
+      const childNewIndent = Math.max(0, childBlock.indent + indentDiff);
+      childBlock.indent = childNewIndent;
+
+      // 마지막일 경우 after Id를 afterNode 로 설정
+      const childReorderOp = editorCRDT.localReorder({
+        targetId: childBlock.id,
+        beforeId: prevBlock.id,
+        afterId: afterNode && index === childBlocks.length - 1 ? afterNode?.id : null,
+        pageId,
+      });
+      operations.push({ type: "reorder", operation: childReorderOp });
+
+      const childUpdateOp = editorCRDT.localUpdate(childBlock, pageId);
+      operations.push({ type: "update", operation: childUpdateOp });
+
+      prevBlock = childBlock;
+    });
+
+    return operations;
+  };
+
+  const handleDragEnd = (
+    event: DragEndEvent,
+    dragBlockList: string[],
+    initDraggingBlock: () => void,
+  ) => {
+    // 커서 다시 원래대로
+    document.body.style.cursor = "auto";
+    initDraggingBlock();
 
-  const handleDragEnd = (event: DragEndEvent) => {
     const { active, over } = event;
+    if (!over) return;
 
-    if (!over || active.id === over.id) return;
+    // 지금 놓으려는 블록(over)이 드래깅 중인 블록이거나, 드래깅 중인 블록의 자식 블록이면 무시
+    const disableDrag = dragBlockList.some((item) => item === over.data.current?.id);
+    if (disableDrag) return;
 
     try {
       const nodes = editorState.linkedList.spread();
@@ -53,13 +143,11 @@ export const useBlockDragAndDrop = ({
         (block) => block.id.client === overInfo.client && block.id.clock === overInfo.clock,
       );
 
-      if (!targetNode || !overNode) {
-        throw new Error("Unable to find target or destination node");
-      }
+      if (!targetNode || !overNode) return;
 
+      // 드래그 방향에 따라 beforeNode와 afterNode 결정
       const targetIndex = nodes.indexOf(targetNode);
       const overIndex = nodes.indexOf(overNode);
-
       // 드래그 방향 결정
       const isMoveDown = targetIndex < overIndex;
 
@@ -76,18 +164,18 @@ export const useBlockDragAndDrop = ({
         beforeNode = overIndex > 0 ? nodes[overIndex - 1] : null;
         afterNode = overNode;
       }
-
       // EditorCRDT의 현재 상태로 작업
-      const operation = editorCRDT.localReorder({
-        targetId: targetNode.id,
-        beforeId: beforeNode?.id || null,
-        afterId: afterNode?.id || null,
-        pageId,
+      const operations = reorderBlocksWithChildren(nodes, targetNode, beforeNode, afterNode);
+
+      // 각 operation type에 따라 함수 호출 (reorder + update(indent 갱신))
+      operations.forEach((op) => {
+        if (op.type === "reorder") {
+          sendBlockReorderOperation(op.operation as RemoteBlockReorderOperation);
+        } else if (op.type === "update") {
+          sendBlockUpdateOperation(op.operation as RemoteBlockUpdateOperation);
+        }
       });
 
-      sendBlockReorderOperation(operation);
-
-      // EditorState 업데이트
       setEditorState({
         clock: editorCRDT.clock,
         linkedList: editorCRDT.LinkedList,
@@ -97,8 +185,45 @@ export const useBlockDragAndDrop = ({
     }
   };
 
+  const handleDragStart = (
+    event: DragStartEvent,
+    setDragBlockList: React.Dispatch<React.SetStateAction<string[]>>,
+  ) => {
+    document.body.style.cursor = "grabbing";
+    const { active } = event;
+    const parentId = active.data.current?.id;
+    const parentIndent = active.data.current?.block.indent;
+
+    if (!parentId) return;
+
+    const findChildBlocks = (parentId: string) => {
+      const blocks = editorState.linkedList.spread();
+      const parentIndex = blocks.findIndex(
+        (block) => `${block.id.client}-${block.id.clock}` === parentId,
+      );
+
+      if (parentIndex === -1) return [];
+
+      const childBlockIds = [];
+
+      for (let i = parentIndex + 1; i < blocks.length; i++) {
+        if (blocks[i].indent > parentIndent) {
+          childBlockIds.push(`${blocks[i].id.client}-${blocks[i].id.clock}`);
+        } else {
+          break;
+        }
+      }
+
+      return childBlockIds;
+    };
+
+    const childBlockIds = findChildBlocks(parentId);
+    setDragBlockList([parentId, ...childBlockIds]);
+  };
+
   return {
     sensors,
     handleDragEnd,
+    handleDragStart,
   };
 };
diff --git a/client/src/features/editor/hooks/useEditorOperation.ts b/client/src/features/editor/hooks/useEditorOperation.ts
index 2917c6c5..84656b07 100644
--- a/client/src/features/editor/hooks/useEditorOperation.ts
+++ b/client/src/features/editor/hooks/useEditorOperation.ts
@@ -47,7 +47,7 @@ export const useEditorOperation = ({
       const prevBlock = editorCRDT.current.LinkedList.nodeMap[JSON.stringify(targetBlock.prev)];
       const nextBlock = editorCRDT.current.LinkedList.nodeMap[JSON.stringify(targetBlock.next)];
       editorCRDT.current.remoteDelete(operation);
-      if (prevBlock.type === "ol" && nextBlock.type === "ol") {
+      if (prevBlock && prevBlock.type === "ol" && nextBlock.type === "ol") {
         editorCRDT.current.LinkedList.updateAllOrderedListIndices();
       }
       setEditorState({
@@ -93,7 +93,7 @@ export const useEditorOperation = ({
       if (operation.pageId !== pageId) return;
       const prevBlock = editorCRDT.current.LinkedList.nodeMap[JSON.stringify(operation.node.prev)];
       editorCRDT.current.remoteUpdate(operation.node, operation.pageId);
-      if (prevBlock.type === "ol") {
+      if (prevBlock && prevBlock.type === "ol") {
         editorCRDT.current.LinkedList.updateAllOrderedListIndices();
       }
       setEditorState({
diff --git a/client/src/features/editor/hooks/useMarkdownGrammer.ts b/client/src/features/editor/hooks/useMarkdownGrammer.ts
index 5ad1234f..e2be299a 100644
--- a/client/src/features/editor/hooks/useMarkdownGrammer.ts
+++ b/client/src/features/editor/hooks/useMarkdownGrammer.ts
@@ -64,6 +64,44 @@ export const useMarkdownGrammer = ({
         return editorCRDT.LinkedList.findByIndex(index);
       };
 
+      const decreaseIndent = (currentBlock: Block) => {
+        if (currentBlock.indent === 0) return;
+
+        const currentIndex = editorCRDT.LinkedList.spread().findIndex((block) =>
+          block.id.equals(currentBlock.id),
+        );
+
+        // 현재 블록의 indent 감소
+        const wasOrderedList = currentBlock.type === "ol";
+        const originalIndent = currentBlock.indent;
+        const newIndent = originalIndent - 1;
+        currentBlock.indent = newIndent;
+        sendBlockUpdateOperation(editorCRDT.localUpdate(currentBlock, pageId));
+
+        // 자식 블록들 찾기 및 업데이트
+        const blocks = editorCRDT.LinkedList.spread();
+        let i = currentIndex + 1;
+
+        // 현재 블록의 원래 indent보다 큰 블록들만 처리 (자식 블록들만)
+        while (i < blocks.length && blocks[i].indent > originalIndent) {
+          const childBlock = blocks[i];
+
+          // 자식 블록의 indent도 1 감소
+          childBlock.indent = Math.max(0, childBlock.indent - 1);
+          sendBlockUpdateOperation(editorCRDT.localUpdate(childBlock, pageId));
+
+          i += 1;
+        }
+
+        // ordered list인 경우 인덱스 업데이트
+        if (wasOrderedList) {
+          editorCRDT.LinkedList.updateAllOrderedListIndices();
+        }
+
+        editorCRDT.currentBlock = currentBlock;
+        updateEditorState();
+      };
+
       const currentBlockId = editorCRDT.currentBlock ? editorCRDT.currentBlock.id : null;
       if (!currentBlockId) return;
 
@@ -166,14 +204,7 @@ export const useMarkdownGrammer = ({
           if (currentContent === "") {
             e.preventDefault();
             if (currentBlock.indent > 0) {
-              const wasOrderedList = currentBlock.type === "ol";
-              currentBlock.indent -= 1;
-              sendBlockUpdateOperation(editorCRDT.localUpdate(currentBlock, pageId));
-              editorCRDT.currentBlock = currentBlock;
-              if (wasOrderedList) {
-                editorCRDT.LinkedList.updateAllOrderedListIndices();
-              }
-              updateEditorState();
+              decreaseIndent(currentBlock);
               break;
             }
 
@@ -252,10 +283,7 @@ export const useMarkdownGrammer = ({
             const currentCaretPosition = currentBlock.crdt.currentCaret;
             if (currentCaretPosition === 0) {
               if (currentBlock.indent > 0) {
-                currentBlock.indent -= 1;
-                sendBlockUpdateOperation(editorCRDT.localUpdate(currentBlock, pageId));
-                editorCRDT.currentBlock = currentBlock;
-                updateEditorState();
+                decreaseIndent(currentBlock);
                 break;
               }
               if (currentBlock.type !== "p") {
@@ -332,18 +360,20 @@ export const useMarkdownGrammer = ({
             if (e.shiftKey) {
               // shift + tab: 들여쓰기 감소
               if (currentBlock.indent > 0) {
-                const isOrderedList = currentBlock.type === "ol";
-                currentBlock.indent -= 1;
-                sendBlockUpdateOperation(editorCRDT.localUpdate(currentBlock, pageId));
-                editorCRDT.currentBlock = currentBlock;
-                if (isOrderedList) {
-                  editorCRDT.LinkedList.updateAllOrderedListIndices();
-                }
-                updateEditorState();
+                decreaseIndent(currentBlock);
               }
             } else {
-              // tab: 들여쓰기 증가
-              const maxIndent = 3;
+              if (!currentBlock.prev) return;
+
+              const parentIndent =
+                editorCRDT.LinkedList.nodeMap[JSON.stringify(currentBlock.prev)].indent;
+
+              const maxIndent = Math.min(
+                parentIndent + 1, // 부모 indent + 1
+                2, // 들여쓰기 최대 indent
+              );
+
+              // 현재 indent가 허용된 최대값보다 작을 때만 들여쓰기 증가
               if (currentBlock.indent < maxIndent) {
                 const isOrderedList = currentBlock.type === "ol";
                 currentBlock.indent += 1;