diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 04e21338dc..d10ec1d749 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -40,6 +40,7 @@ export { Downsampling } from "./enums/Downsampling";
 export { ColorSpace } from "./enums/ColorSpace";
 export { BackgroundTextureFillMode } from "./enums/BackgroundTextureFillMode";
 export { XRManager } from "./xr/XRManager";
+export * from "./utils/index";
 export * from "./input/index";
 export * from "./lighting/index";
 export * from "./shadow/index";
diff --git a/packages/core/src/utils/ClearableObjectPool.ts b/packages/core/src/utils/ClearableObjectPool.ts
index ef3e1d4c5d..a48ef7e222 100644
--- a/packages/core/src/utils/ClearableObjectPool.ts
+++ b/packages/core/src/utils/ClearableObjectPool.ts
@@ -11,6 +11,9 @@ export class ClearableObjectPool<T extends IPoolElement> extends ObjectPool<T> {
     this._elements = [];
   }
 
+  /**
+   * Get an object.
+   */
   get(): T {
     const { _usedElementCount: usedElementCount, _elements: elements } = this;
     this._usedElementCount++;
@@ -23,6 +26,9 @@ export class ClearableObjectPool<T extends IPoolElement> extends ObjectPool<T> {
     }
   }
 
+  /**
+   * Clear used object count to 0, not destroy any object, just change index.
+   */
   clear(): void {
     this._usedElementCount = 0;
   }
diff --git a/packages/core/src/utils/ObjectPool.ts b/packages/core/src/utils/ObjectPool.ts
index ea805830e8..5b5cab525b 100644
--- a/packages/core/src/utils/ObjectPool.ts
+++ b/packages/core/src/utils/ObjectPool.ts
@@ -17,6 +17,12 @@ export abstract class ObjectPool<T extends IPoolElement> {
   abstract get(): T;
 }
 
+/**
+ * The basic interface for Object Pool's element.
+ */
 export interface IPoolElement {
+  /**
+   * Called when the object need be release.
+   */
   dispose?(): void;
 }
diff --git a/packages/core/src/utils/ReturnableObjectPool.ts b/packages/core/src/utils/ReturnableObjectPool.ts
index 58ce9550fd..7a1aa8ccc7 100644
--- a/packages/core/src/utils/ReturnableObjectPool.ts
+++ b/packages/core/src/utils/ReturnableObjectPool.ts
@@ -15,6 +15,9 @@ export class ReturnableObjectPool<T extends IPoolElement> extends ObjectPool<T>
     }
   }
 
+  /**
+   * Get an object from the pool.
+   */
   get(): T {
     if (this._lastElementIndex < 0) {
       return new this._type();
@@ -22,6 +25,9 @@ export class ReturnableObjectPool<T extends IPoolElement> extends ObjectPool<T>
     return this._elements[this._lastElementIndex--];
   }
 
+  /**
+   * Return an object to the pool.
+   */
   return(element: T): void {
     this._elements[++this._lastElementIndex] = element;
   }
diff --git a/packages/core/src/utils/index.ts b/packages/core/src/utils/index.ts
new file mode 100644
index 0000000000..ab2155d40c
--- /dev/null
+++ b/packages/core/src/utils/index.ts
@@ -0,0 +1,3 @@
+export { ClearableObjectPool } from "./ClearableObjectPool";
+export type { IPoolElement } from "./ObjectPool";
+export { ReturnableObjectPool } from "./ReturnableObjectPool";