diff --git a/src/interfaces.ts b/src/interfaces.ts
index 4cc846c..a38f360 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -1,4 +1,4 @@
-import { Address, Amount, Script, CellDep, Transaction } from './models';
+import { Script, CellDep } from './models';
 
 export interface CKBModel {
   validate(): any;
@@ -16,32 +16,6 @@ export enum DepType {
   depGroup = 'dep_group',
 }
 
-export interface BlockHeader {
-  compact_target: string;
-  number: string;
-  parent_hash: string;
-  nonce: string;
-  timestamp: string;
-  transactions_root: string;
-  proposals_hash: string;
-  uncles_hash: string;
-  version: string;
-  epoch: string;
-  dao: string;
-}
-
-export interface Block {
-  header: BlockHeader;
-  transactions: Transaction[];
-  proposals: string[];
-  uncles: string[];
-}
-
-export interface CellbaseWitness {
-  lock: Script;
-  message: string;
-}
-
 export interface WitnessArgs {
   lock: string;
   input_type: string;
@@ -60,8 +34,3 @@ export interface Config {
   multiSigLock: ConfigItem;
   pwLock: ConfigItem;
 }
-
-export interface ReceivePair {
-  address: Address;
-  amount: Amount;
-}
diff --git a/src/models/address.ts b/src/models/address.ts
index 7c4fed5..a226cdd 100644
--- a/src/models/address.ts
+++ b/src/models/address.ts
@@ -66,20 +66,6 @@ export class Address {
         hashType === HashType.data ? AType.DataCodeHash : AType.TypeCodeHash,
       prefix: APrefix[getDefaultPrefix()],
     });
-
-    /*
-    const script = transformers.TransformScript(this.toLockScript());
-    validators.ValidateScript(script);
-    const script1 = new LumosScript(SerializeScript(script));
-    throw new Error('[toCKBAddress] script' + JSON.stringify(script1));
-
-    return generateAddress(
-      { ...script, hash_type: 1 },
-      {
-        config: LumosConfigs[this.addressType],
-      }
-    );
-    */
   }
 
   toLockScript(): Script {
diff --git a/src/models/cell-dep.ts b/src/models/cell-dep.ts
index 850cfef..faf32b2 100644
--- a/src/models/cell-dep.ts
+++ b/src/models/cell-dep.ts
@@ -4,6 +4,7 @@ import { validators, transformers } from 'ckb-js-toolkit';
 
 export class CellDep implements CKBModel {
   static fromRPC(data: any): CellDep {
+    if (!data) return null;
     validators.ValidateCellDep(data);
     return new CellDep(data.dep_type, data.out_point);
   }
diff --git a/src/models/cell-input.ts b/src/models/cell-input.ts
index de6fb5a..661faa2 100644
--- a/src/models/cell-input.ts
+++ b/src/models/cell-input.ts
@@ -4,6 +4,7 @@ import { validators, transformers } from 'ckb-js-toolkit';
 
 export class CellInput implements CKBModel {
   static fromRPC(data: any): CellInput {
+    if (!data) return null;
     validators.ValidateCellInput(data);
     return new CellInput(data.previous_output, data.since);
   }
diff --git a/src/models/cell.ts b/src/models/cell.ts
index 518b1e4..9270fe6 100644
--- a/src/models/cell.ts
+++ b/src/models/cell.ts
@@ -1,12 +1,11 @@
 import { CKBModel } from '../interfaces';
-import { utf8ToHex, hexToUtf8 } from '@nervosnetwork/ckb-sdk-utils';
 import { Amount, Script, OutPoint } from '.';
 import { CellInput } from './cell-input';
 // import { minimalCellCapacity } from '../utils';
 import { AmountUnit } from './amount';
-import { RPC, validators, transformers, normalizers } from 'ckb-js-toolkit';
+import { RPC, validators, transformers } from 'ckb-js-toolkit';
 import { HashType } from '..';
-import { SerializeCellOutput } from '@ckb-lumos/types/lib/core';
+import { byteArrayToHex, hexToByteArray } from '../utils';
 
 export class Cell implements CKBModel {
   static fromRPC(data: any): Cell {
@@ -58,12 +57,13 @@ export class Cell implements CKBModel {
   }
 
   resize() {
-    const base = SerializeCellOutput(
-      normalizers.NormalizeCellOutput(transformers.TransformCellOutput(this))
-    ).byteLength;
-    const extra = new Buffer(this.data, 'hex').byteLength;
+    // const base = SerializeCellOutput(
+    //   normalizers.NormalizeCellOutput(transformers.TransformCellOutput(this))
+    // ).byteLength;
+    const base = this.type ? 102 : 61;
+    const extra = new Buffer(this.data.replace('0x', ''), 'hex').byteLength;
     const size = base + extra;
-    this.capacity = new Amount(size.toString(), AmountUnit.ckb);
+    this.capacity = new Amount(size.toString());
     return size;
   }
 
@@ -97,7 +97,12 @@ export class Cell implements CKBModel {
   }
 
   setData(data: string) {
-    this.data = utf8ToHex(data.trim());
+    data = data.trim();
+    const bytes = [];
+    for (let i = 0; i < data.length; i++) {
+      bytes.push(data.charCodeAt(i));
+    }
+    this.data = byteArrayToHex(bytes);
     this.spaceCheck();
   }
 
@@ -111,7 +116,9 @@ export class Cell implements CKBModel {
   }
 
   getData(): string {
-    return hexToUtf8(this.data.trim());
+    return hexToByteArray(this.data.trim())
+      .map((char) => String.fromCharCode(char))
+      .join('');
   }
 
   getHexData(): string {
diff --git a/src/models/script.ts b/src/models/script.ts
index c00c6c8..e28122a 100644
--- a/src/models/script.ts
+++ b/src/models/script.ts
@@ -1,19 +1,17 @@
 import { HashType, CKBModel } from '../interfaces';
 import { scriptToHash } from '@nervosnetwork/ckb-sdk-utils';
-// import { SerializeScript } from '@ckb-lumos/types/lib/core';
 import {
   Address,
   AddressType,
   AddressPrefix,
   getDefaultPrefix,
 } from './address';
-// import { Blake2bHasher } from '../hasher';
-// import { Reader } from 'ckb-js-toolkit';
 import { generateAddress, LumosConfigs } from '../utils';
 import { validators, transformers } from 'ckb-js-toolkit';
 
 export class Script implements CKBModel {
   static fromRPC(data: any): Script | null {
+    if (!data) return null;
     validators.ValidateScript(data);
     return new Script(data.code_hash, data.args, data.hash_type);
   }
@@ -48,12 +46,6 @@ export class Script implements CKBModel {
 
   toHash(): string {
     return scriptToHash(this);
-    /*
-    const serializedScript = SerializeScript(this.serializeJson());
-    return new Blake2bHasher()
-      .hash(new Reader(serializedScript))
-      .serializeJson();
-      */
   }
 
   toAddress(prefix: AddressPrefix = getDefaultPrefix()): Address {
diff --git a/src/models/transaction.ts b/src/models/transaction.ts
index 5a0880f..9f69583 100644
--- a/src/models/transaction.ts
+++ b/src/models/transaction.ts
@@ -7,6 +7,7 @@ import { SerializeTransaction } from '@ckb-lumos/types/lib/core';
 import { RawTransaction } from '.';
 
 export class Transaction implements CKBModel {
+  // TODO: add WitnessArgs to adapt different transaction structures
   public witnesses: string[];
 
   constructor(
diff --git a/src/utils.ts b/src/utils.ts
index 14df43c..55cd708 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -27,19 +27,19 @@ export const shannonToCKB = (
     fraction = `0${fraction}`;
   }
 
-  if (!options?.pad) {
+  if (options && !options.pad) {
     fraction = fraction.match(/^([0-9]*[1-9]|0)(0*)/)[1];
   }
 
   let whole = JSBI.divide(amount, base).toString(10);
 
-  if (options?.commify) {
+  if (options && options.commify) {
     whole = whole.replace(/\B(?=(\d{3})+(?!\d))/g, ',');
   }
 
   let result = `${whole}${fraction === '0' ? '' : `.${fraction}`}`;
 
-  if (options?.section === 'whole') {
+  if (options && options.section === 'whole') {
     result = whole;
   }
 
@@ -47,7 +47,7 @@ export const shannonToCKB = (
     result = `-${result}`;
   }
 
-  if (options?.section === 'fraction') {
+  if (options && options.section === 'fraction') {
     result = fraction;
   }
 
@@ -80,7 +80,7 @@ export const ckbToShannon = (ckbAmount: string): string => {
   return result.toString();
 };
 
-// from helper
+// from @lumos/helper
 
 const LINA = {
   PREFIX: 'ckb',
@@ -229,9 +229,6 @@ export function parseAddress(address, { config = LINA } = {}) {
       if (!scriptTemplate) {
         throw Error(`Invalid code hash index: ${data[1]}!`);
       }
-      // return Object.assign({}, scriptTemplate.SCRIPT, {
-      //   args: byteArrayToHex(data.slice(2)),
-      // });
       return { ...scriptTemplate.SCRIPT, args: byteArrayToHex(data.slice(2)) };
     case 2:
       if (data.length < 33) {
diff --git a/yarn.lock b/yarn.lock
index 796c725..f9114e6 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -203,26 +203,6 @@
     typedoc-default-themes "^0.6.0-0"
     typescript "3.5.x"
 
-"@ckb-lumos/common-scripts@^0.2.4":
-  version "0.2.4"
-  resolved "https://registry.npm.taobao.org/@ckb-lumos/common-scripts/download/@ckb-lumos/common-scripts-0.2.4.tgz#d73602505408976f8541f530477a73ba7c3b88e8"
-  integrity sha1-1zYCUFQIl2+FQfUwR3pzunw7iOg=
-  dependencies:
-    "@ckb-lumos/helpers" "^0.2.4"
-    "@ckb-lumos/types" "^0.2.4"
-    ckb-js-toolkit "^0.9.1"
-    immutable "^4.0.0-rc.12"
-
-"@ckb-lumos/helpers@^0.2.4":
-  version "0.2.4"
-  resolved "https://registry.npm.taobao.org/@ckb-lumos/helpers/download/@ckb-lumos/helpers-0.2.4.tgz#b9902c405e49b8a3874cd1ecdd7e72ec6d0f1b5c"
-  integrity sha1-uZAsQF5JuKOHTNHs3X5y7G0PG1w=
-  dependencies:
-    "@ckb-lumos/types" "^0.2.4"
-    bech32 "^1.1.4"
-    ckb-js-toolkit "^0.9.1"
-    immutable "^4.0.0-rc.12"
-
 "@ckb-lumos/types@^0.2.4":
   version "0.2.4"
   resolved "https://registry.npm.taobao.org/@ckb-lumos/types/download/@ckb-lumos/types-0.2.4.tgz#1733d29a7489af8ddfc297a240249fb3046fda7a"