diff --git a/.Lib9c.Tests/Action/SynthesizeTest.cs b/.Lib9c.Tests/Action/SynthesizeTest.cs
index cda7f63720..db8ae19d23 100644
--- a/.Lib9c.Tests/Action/SynthesizeTest.cs
+++ b/.Lib9c.Tests/Action/SynthesizeTest.cs
@@ -256,6 +256,14 @@ public void ExecuteMultiple(Grade grade, ItemSubType itemSubType)
             if (result.IsSuccess)
             {
                 Assert.Equal((int)grade + 1, result.ItemBase.Grade);
+
+                var weightSheet = TableSheets.SynthesizeWeightSheet;
+                var weightRow = weightSheet.Values.FirstOrDefault(r => r.ItemId == result.ItemBase.Id);
+
+                if (weightRow != null)
+                {
+                    Assert.True(weightRow.Weight != 0);
+                }
             }
             else
             {
diff --git a/Lib9c/Helper/SynthesizeSimulator.cs b/Lib9c/Helper/SynthesizeSimulator.cs
index 8bab8c5df9..e5d1493413 100644
--- a/Lib9c/Helper/SynthesizeSimulator.cs
+++ b/Lib9c/Helper/SynthesizeSimulator.cs
@@ -384,7 +384,7 @@ private static ItemBase GetRandomCostume(Grade grade, bool isSuccess, ItemSubTyp
                 throw new InvalidOperationException($"No available items to synthesize for grade {grade} and subtype {itemSubType}");
             }
 
-            var randomValue = GetRandomValueForItem(grade, synthesizeResultPool, weightSheet, random, out var itemWeights);
+            var randomValue = GetRandomValueForItem(synthesizeResultPool, weightSheet, random, out var itemWeights);
             var cumulativeWeight = 0;
             foreach (var (itemId, weight) in itemWeights)
             {
@@ -440,7 +440,7 @@ private static ItemBase GetRandomEquipment(
                 throw new InvalidOperationException($"No available items to synthesize for grade {grade} and subtype {itemSubType}");
             }
 
-            var randomValue = GetRandomValueForItem(grade, synthesizeResultPool, weightSheet, random, out var itemWeights);
+            var randomValue = GetRandomValueForItem(synthesizeResultPool, weightSheet, random, out var itemWeights);
             var cumulativeWeight = 0;
             foreach (var (itemId, weight) in itemWeights)
             {
@@ -506,14 +506,14 @@ private static ItemBase GetRandomEquipment(
             throw new InvalidOperationException("Failed to select a synthesized item.");
         }
 
-        private static int GetRandomValueForItem(Grade grade, HashSet<int> synthesizeResultPool, SynthesizeWeightSheet synthesizeWeightSheet,
+        private static int GetRandomValueForItem(HashSet<int> synthesizeResultPool, SynthesizeWeightSheet synthesizeWeightSheet,
                                           IRandom random, out List<(int ItemId, int Weight)> itemWeights)
         {
             var totalWeight = 0;
             itemWeights = new List<(int ItemId, int Weight)>();
             foreach (var itemId in synthesizeResultPool)
             {
-                var weight = GetWeight(grade, itemId, synthesizeWeightSheet);
+                var weight = GetWeight(itemId, synthesizeWeightSheet);
                 itemWeights.Add((itemId, weight));
                 totalWeight += weight;
             }
@@ -631,11 +631,11 @@ public static Grade GetUpgradeGrade(Grade grade ,ItemSubType subType, EquipmentI
         /// <param name="itemId">item id of material item</param>
         /// <param name="sheet">SynthesizeWeightSheet to use</param>
         /// <returns>weight of the item that can be obtained by synthesizing the item</returns>
-        public static int GetWeight(Grade grade, int itemId, SynthesizeWeightSheet sheet)
+        public static int GetWeight(int itemId, SynthesizeWeightSheet sheet)
         {
             var defaultWeight = SynthesizeWeightSheet.DefaultWeight;
-            var gradeRow = sheet.Values.FirstOrDefault(r => r.GradeId == (int)grade);
-            return gradeRow == null ? defaultWeight : gradeRow.WeightDict.GetValueOrDefault(itemId, defaultWeight);
+            var gradeRow = sheet.Values.FirstOrDefault(r => r.Key == itemId);
+            return gradeRow?.Weight ?? defaultWeight;
         }
 
         // TODO: move to ItemExtensions
diff --git a/Lib9c/TableCSV/Item/SynthesizeWeightSheet.csv b/Lib9c/TableCSV/Item/SynthesizeWeightSheet.csv
index c808bb9e0b..afed6fd97f 100644
--- a/Lib9c/TableCSV/Item/SynthesizeWeightSheet.csv
+++ b/Lib9c/TableCSV/Item/SynthesizeWeightSheet.csv
@@ -1,7 +1,8 @@
-grade_id,item_id,weight
+item_id,weight
 _default value for weight is 10000.
-3,40100001,3000
-3,40100015,1000
-3,40100016,1000
-3,40100019,1000
-5,49900027,40000
\ No newline at end of file
+40100001,3000
+40100015,1000
+40100016,1000
+40100017,0
+40100019,1000
+49900027,40000
\ No newline at end of file
diff --git a/Lib9c/TableData/Item/SynthesizeWeightSheet.cs b/Lib9c/TableData/Item/SynthesizeWeightSheet.cs
index 35b270b95a..f5e02e90aa 100644
--- a/Lib9c/TableData/Item/SynthesizeWeightSheet.cs
+++ b/Lib9c/TableData/Item/SynthesizeWeightSheet.cs
@@ -17,42 +17,20 @@ public class SynthesizeWeightSheet : Sheet<int, SynthesizeWeightSheet.Row>
         [Serializable]
         public class Row : SheetRow<int>
         {
-            public override int Key => GradeId;
+            public override int Key => ItemId;
 
-            public int GradeId { get; private set; }
-
-            public Dictionary<int, int> WeightDict { get; private set; }
+            public int ItemId { get; private set; }
+            public int Weight { get; private set; }
 
             public override void Set(IReadOnlyList<string> fields)
             {
-                GradeId = ParseInt(fields[0]);
-
-                WeightDict = new Dictionary<int, int>();
-                var itemId = ParseInt(fields[1]);
-                var weight = ParseInt(fields[2], DefaultWeight);
-                WeightDict.Add(itemId, weight);
+                ItemId = ParseInt(fields[0]);
+                Weight = TryParseInt(fields[1], out var weight) ? weight : DefaultWeight;
             }
         }
 
         public SynthesizeWeightSheet() : base(nameof(SynthesizeWeightSheet))
         {
         }
-
-        protected override void AddRow(int key, Row value)
-        {
-            if (!TryGetValue(key, out var row))
-            {
-                Add(key, value);
-
-                return;
-            }
-
-            if (!value.WeightDict.Any())
-            {
-                return;
-            }
-
-            row.WeightDict.TryAdd(value.WeightDict.First().Key, value.WeightDict.First().Value);
-        }
     }
 }