diff --git a/app/Endpoint/Api/Http/Controllers/ShoppingCartItemController.php b/app/Endpoint/Api/Http/Controllers/ShoppingCartItemController.php
index 112aa77d..da2504dc 100644
--- a/app/Endpoint/Api/Http/Controllers/ShoppingCartItemController.php
+++ b/app/Endpoint/Api/Http/Controllers/ShoppingCartItemController.php
@@ -3,6 +3,7 @@
 namespace App\Endpoint\Api\Http\Controllers;
 
 use App\Endpoint\Api\Http\Resources\ShoppingCartItemResource;
+use App\Exceptions\ProductNotEnoughException;
 use App\Exceptions\ProductOfflineException;
 use App\Models\ProductSku;
 use Illuminate\Http\Request;
@@ -40,7 +41,11 @@ class ShoppingCartItemController extends Controller
             throw new ProductOfflineException();
         }
 
-        $item = $request->user()->shoppingCartItems()->firstOrCreate([
+        if ($input['quantity'] > $sku->saleable_stock) {
+            throw new ProductNotEnoughException();
+        }
+
+        $shoppingCartItem = $request->user()->shoppingCartItems()->firstOrCreate([
             'sku_id' => $sku->id,
         ], [
             'name' => $sku->name,
@@ -51,8 +56,12 @@ class ShoppingCartItemController extends Controller
             'quantity' => $input['quantity'],
         ]);
 
-        if (! $item->wasRecentlyCreated) {
-            $item->increment('quantity', $input['quantity']);
+        if (! $shoppingCartItem->wasRecentlyCreated) {
+            if ($shoppingCartItem->quantity + $input['quantity'] > $sku->saleable_stock) {
+                throw new ProductNotEnoughException();
+            }
+
+            $shoppingCartItem->increment('quantity', $input['quantity']);
         }
 
         return response()->noContent();
@@ -71,13 +80,17 @@ class ShoppingCartItemController extends Controller
             'quantity' => ['bail', 'required', 'int', 'min:1'],
         ]);
 
-        $item = $request->user()->shoppingCartItems()->findOrFail($id);
+        $shoppingCartItem = $request->user()->shoppingCartItems()->findOrFail($id);
 
-        if (is_null($sku = $item->sku()->online()->first())) {
+        if (is_null($sku = $shoppingCartItem->sku()->online()->first())) {
             throw new ProductOfflineException();
         }
 
-        $item->update(array_merge($input, [
+        if ($input['quantity'] > $sku->saleable_stock) {
+            throw new ProductNotEnoughException();
+        }
+
+        $shoppingCartItem->update(array_merge($input, [
             'name' => $sku->name,
             'cover' => $sku->cover,
             'sell_price' => $sku->sell_price,
diff --git a/app/Exceptions/ProductNotEnoughException.php b/app/Exceptions/ProductNotEnoughException.php
new file mode 100644
index 00000000..e4ba8258
--- /dev/null
+++ b/app/Exceptions/ProductNotEnoughException.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace App\Exceptions;
+
+class ProductNotEnoughException extends BizException
+{
+    public function __construct(string $message = '商品库存不足')
+    {
+        parent::__construct($message);
+    }
+}