diff --git a/.changeset/angry-rabbits-refuse.md b/.changeset/angry-rabbits-refuse.md
new file mode 100644
index 000000000..58c94eae8
--- /dev/null
+++ b/.changeset/angry-rabbits-refuse.md
@@ -0,0 +1,5 @@
+---
+"@ckb-lumos/base": minor
+---
+
+**BREAKING CHANGE**: remove unused `isDeepEqual` function to reduce the package size
diff --git a/packages/base/package.json b/packages/base/package.json
index 154755da1..6d2aff77f 100644
--- a/packages/base/package.json
+++ b/packages/base/package.json
@@ -50,11 +50,11 @@
     "@types/blake2b": "^2.1.0",
     "@types/lodash.isequal": "^4.5.5",
     "blake2b": "^2.1.3",
-    "js-xxhash": "^1.0.4",
-    "lodash.isequal": "^4.5.0"
+    "js-xxhash": "^1.0.4"
   },
   "devDependencies": {
-    "jsbi": "^4.1.0"
+    "jsbi": "^4.1.0",
+    "lodash.isequal": "^4.5.0"
   },
   "publishConfig": {
     "access": "public"
diff --git a/packages/base/src/utils.ts b/packages/base/src/utils.ts
index 7c269e4a2..b952803b0 100644
--- a/packages/base/src/utils.ts
+++ b/packages/base/src/utils.ts
@@ -1,5 +1,4 @@
 import blake2b, { Blake2b } from "blake2b";
-import isEqual from "lodash.isequal";
 import { xxHash32 } from "js-xxhash";
 import { bytes, number, BytesLike } from "@ckb-lumos/codec";
 import { BI, BIish } from "@ckb-lumos/bi";
@@ -149,10 +148,6 @@ function assertHexadecimal(debugPath: string, str: string): void {
   }
 }
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/explicit-module-boundary-types
-function isDeepEqual(a: any, b: any): boolean {
-  return isEqual(a, b);
-}
 // Buffer.from('TYPE_ID')
 const TYPE_ID_CODE_HASH =
   "0x00000000000000000000000000000000000000000000000000545950455f4944";
@@ -272,6 +267,5 @@ export {
   hashCode,
   assertHexString,
   assertHexadecimal,
-  isDeepEqual,
   generateTypeIdScript,
 };
diff --git a/packages/base/tests/since.test.js b/packages/base/tests/since.test.js
index bfff204a9..33a6e6e25 100644
--- a/packages/base/tests/since.test.js
+++ b/packages/base/tests/since.test.js
@@ -1,7 +1,8 @@
 const test = require("ava");
+const isEqual = require("lodash.isequal");
 const { BI } = require("@ckb-lumos/bi");
 
-const { since, utils } = require("../src");
+const { since } = require("../src");
 
 const {
   parseSinceCompatible,
@@ -91,7 +92,7 @@ test.before(() => {
 test("parsedSince", (t) => {
   fixtrues.forEach((v) => {
     const parsed = parseSinceCompatible(v.since);
-    t.true(utils.isDeepEqual(parsed, v.parsed));
+    t.true(isEqual(parsed, v.parsed));
   });
 });
 
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3e989cd0d..098b65758 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -143,13 +143,13 @@ importers:
       js-xxhash:
         specifier: ^1.0.4
         version: 1.0.4
-      lodash.isequal:
-        specifier: ^4.5.0
-        version: 4.5.0
     devDependencies:
       jsbi:
         specifier: ^4.1.0
         version: 4.3.0
+      lodash.isequal:
+        specifier: ^4.5.0
+        version: 4.5.0
 
   packages/bi:
     dependencies:
@@ -11493,7 +11493,7 @@ packages:
 
   /lodash.isequal@4.5.0:
     resolution: {integrity: sha512-pDo3lu8Jhfjqls6GkMgpahsF9kCyayhgykjyLMNFTKWrpVdAQtYyB4muAMWozBB4ig/dtWAmsMxLEI8wuz+DYQ==}
-    dev: false
+    dev: true
 
   /lodash.memoize@4.1.2:
     resolution: {integrity: sha512-t7j+NzmgnQzTAYXcsHYLgimltOV1MXHtlOWf6GjL9Kj8GK5FInw5JotxvbOs+IvV1/Dzo04/fCGfLVs7aXb4Ag==}