diff --git a/src/index.ts b/src/index.ts
index 4094a969..dd4316d6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,10 +1,11 @@
-import Theme, { createTheme } from './Theme';
-import type { TokenType } from './Theme';
+import Theme from './theme/Theme';
 import useStyleRegister, { extractStyle } from './useStyleRegister';
 import type { CSSObject, CSSInterpolation } from './useStyleRegister';
 import useCacheToken from './useCacheToken';
 import { StyleProvider, createCache } from './StyleContext';
 import Keyframes from './Keyframes';
+import type { TokenType } from './theme';
+import { createTheme } from './theme';
 
 export {
   Theme,
diff --git a/src/theme/Theme.ts b/src/theme/Theme.ts
new file mode 100644
index 00000000..16ee58fb
--- /dev/null
+++ b/src/theme/Theme.ts
@@ -0,0 +1,41 @@
+import { warning } from 'rc-util/lib/warning';
+import type { DerivativeFunc, TokenType } from './interface';
+
+let uuid = 0;
+
+/**
+ * Theme with algorithms to derive tokens from design tokens.
+ * Use `createTheme` first which will help to manage the theme instance cache.
+ */
+export default class Theme<
+  DesignToken extends TokenType,
+  DerivativeToken extends TokenType,
+> {
+  private derivatives: DerivativeFunc<DesignToken, DerivativeToken>[];
+  public readonly id: number;
+
+  constructor(
+    derivatives:
+      | DerivativeFunc<DesignToken, DerivativeToken>
+      | DerivativeFunc<DesignToken, DerivativeToken>[],
+  ) {
+    this.derivatives = Array.isArray(derivatives) ? derivatives : [derivatives];
+    this.id = uuid;
+
+    if (derivatives.length === 0) {
+      warning(
+        derivatives.length > 0,
+        '[Ant Design CSS-in-JS] Theme should have at least one derivative function.',
+      );
+    }
+
+    uuid += 1;
+  }
+
+  getDerivativeToken(token: DesignToken): DerivativeToken {
+    return this.derivatives.reduce<DerivativeToken>(
+      (result, derivative) => derivative(token, result),
+      undefined as any,
+    );
+  }
+}
diff --git a/src/Theme.ts b/src/theme/ThemeCache.ts
similarity index 65%
rename from src/Theme.ts
rename to src/theme/ThemeCache.ts
index e0681fc3..633a7363 100644
--- a/src/Theme.ts
+++ b/src/theme/ThemeCache.ts
@@ -1,53 +1,5 @@
-import { warning } from 'rc-util/lib/warning';
-
-export type TokenType = object;
-
-export type DerivativeFunc<
-  DesignToken extends TokenType,
-  DerivativeToken extends TokenType,
-> = (
-  designToken: DesignToken,
-  derivativeToken?: DerivativeToken,
-) => DerivativeToken;
-
-let uuid = 0;
-
-/**
- * Theme with algorithms to derive tokens from design tokens.
- * Use `createTheme` first which will help to manage the theme instance cache.
- */
-export default class Theme<
-  DesignToken extends TokenType,
-  DerivativeToken extends TokenType,
-> {
-  private derivatives: DerivativeFunc<DesignToken, DerivativeToken>[];
-  public readonly id: number;
-
-  constructor(
-    derivatives:
-      | DerivativeFunc<DesignToken, DerivativeToken>
-      | DerivativeFunc<DesignToken, DerivativeToken>[],
-  ) {
-    this.derivatives = Array.isArray(derivatives) ? derivatives : [derivatives];
-    this.id = uuid;
-
-    if (derivatives.length === 0) {
-      warning(
-        derivatives.length > 0,
-        '[Ant Design CSS-in-JS] Theme should have at least one derivative function.',
-      );
-    }
-
-    uuid += 1;
-  }
-
-  getDerivativeToken(token: DesignToken): DerivativeToken {
-    return this.derivatives.reduce<DerivativeToken>(
-      (result, derivative) => derivative(token, result),
-      undefined as any,
-    );
-  }
-}
+import type Theme from './Theme';
+import type { DerivativeFunc } from './interface';
 
 // ================================== Cache ==================================
 type ThemeCacheMap = Map<
@@ -75,7 +27,7 @@ export function sameDerivativeOption(
   return true;
 }
 
-export class ThemeCache {
+export default class ThemeCache {
   public static MAX_CACHE_SIZE = 20;
   public static MAX_CACHE_OFFSET = 5;
 
@@ -194,28 +146,3 @@ export class ThemeCache {
     return undefined;
   }
 }
-
-const cacheThemes = new ThemeCache();
-
-/**
- * Same as new Theme, but will always return same one if `derivative` not changed.
- */
-export function createTheme<
-  DesignToken extends TokenType,
-  DerivativeToken extends TokenType,
->(
-  derivatives:
-    | DerivativeFunc<DesignToken, DerivativeToken>[]
-    | DerivativeFunc<DesignToken, DerivativeToken>,
-) {
-  const derivativeArr = Array.isArray(derivatives)
-    ? derivatives
-    : [derivatives];
-  // Create new theme if not exist
-  if (!cacheThemes.has(derivativeArr)) {
-    cacheThemes.set(derivativeArr, new Theme(derivativeArr));
-  }
-
-  // Get theme from cache and return
-  return cacheThemes.get(derivativeArr)!;
-}
diff --git a/src/theme/createTheme.ts b/src/theme/createTheme.ts
new file mode 100644
index 00000000..2cabaae9
--- /dev/null
+++ b/src/theme/createTheme.ts
@@ -0,0 +1,28 @@
+import ThemeCache from './ThemeCache';
+import Theme from './Theme';
+import { DerivativeFunc, TokenType } from '@/theme/interface';
+
+const cacheThemes = new ThemeCache();
+
+/**
+ * Same as new Theme, but will always return same one if `derivative` not changed.
+ */
+export default function createTheme<
+  DesignToken extends TokenType,
+  DerivativeToken extends TokenType,
+>(
+  derivatives:
+    | DerivativeFunc<DesignToken, DerivativeToken>[]
+    | DerivativeFunc<DesignToken, DerivativeToken>,
+) {
+  const derivativeArr = Array.isArray(derivatives)
+    ? derivatives
+    : [derivatives];
+  // Create new theme if not exist
+  if (!cacheThemes.has(derivativeArr)) {
+    cacheThemes.set(derivativeArr, new Theme(derivativeArr));
+  }
+
+  // Get theme from cache and return
+  return cacheThemes.get(derivativeArr)!;
+}
diff --git a/src/theme/index.ts b/src/theme/index.ts
new file mode 100644
index 00000000..076fe417
--- /dev/null
+++ b/src/theme/index.ts
@@ -0,0 +1,3 @@
+export { default as createTheme } from './createTheme';
+export { default as Theme } from './Theme';
+export type { TokenType, DerivativeFunc } from './interface';
diff --git a/src/theme/interface.ts b/src/theme/interface.ts
new file mode 100644
index 00000000..de52e1ee
--- /dev/null
+++ b/src/theme/interface.ts
@@ -0,0 +1,8 @@
+export type TokenType = object;
+export type DerivativeFunc<
+  DesignToken extends TokenType,
+  DerivativeToken extends TokenType,
+> = (
+  designToken: DesignToken,
+  derivativeToken?: DerivativeToken,
+) => DerivativeToken;
diff --git a/src/useCacheToken.tsx b/src/useCacheToken.tsx
index b43915d7..a7b15ddb 100644
--- a/src/useCacheToken.tsx
+++ b/src/useCacheToken.tsx
@@ -5,7 +5,7 @@ import {
   CSS_IN_JS_INSTANCE,
   CSS_IN_JS_INSTANCE_ID,
 } from './StyleContext';
-import type Theme from './Theme';
+import type Theme from './theme/Theme';
 import useGlobalCache from './useGlobalCache';
 import { flattenToken, token2key } from './util';
 
diff --git a/tests/theme.spec.tsx b/tests/theme.spec.tsx
index 5fd8ca8a..60db78ee 100644
--- a/tests/theme.spec.tsx
+++ b/tests/theme.spec.tsx
@@ -1,7 +1,7 @@
 import { Theme, createTheme, useCacheToken } from '../src';
 import { render } from '@testing-library/react';
 import * as React from 'react';
-import { ThemeCache } from '../src/Theme';
+import ThemeCache from '../src/theme/ThemeCache';
 
 interface DesignToken {
   primaryColor: string;
@@ -189,7 +189,7 @@ describe('Theme', () => {
   });
 
   it('should warn if empty array', () => {
-    const errSpy = jest.spyOn(console, 'error');
+    const errSpy = jest.spyOn(console, 'error').mockImplementation(jest.fn());
     expect(errSpy).toHaveBeenCalledTimes(0);
     createTheme([]);
     expect(errSpy).toHaveBeenCalledTimes(1);