diff --git a/cart.html b/cart.html
index f6d543f..a52df1d 100644
--- a/cart.html
+++ b/cart.html
@@ -66,7 +66,7 @@ <h1 class="mb-3 d-flex align-items-center">
                         <td>${cartProduct.color}</td>
                         <td>${cartProduct.capacity}</td>
                         <td>
-                            <input type="number" class="quantity form-control" id="cart-${cartProduct.id}" value="${cartProduct.quantity}" onChange="updateCart('${cartProduct.id}', '${cartProduct.name}', '${cartProduct.color}', '${cartProduct.capacity}')">
+                            <input type="number" class="quantity form-control" id="cart-${cartProduct.id}" value="${cartProduct.quantity}" min="1" onChange="updateCart('${cartProduct.id}', '${cartProduct.name}', '${cartProduct.color}', '${cartProduct.capacity}')">
                         </td>
                         <td>
                             <button class="btn btn-outline-danger" onclick="deleteCart('${cartProduct.id}')">刪除</button>
diff --git a/product.html b/product.html
index 6fefdf3..cb0500c 100644
--- a/product.html
+++ b/product.html
@@ -36,7 +36,7 @@ <h1 class="mb-3 d-flex align-items-center">
             <div class="d-flex align-items-center mb-5">
                 <div class="me-2">數量</div>
                 <div class="col-auto">
-                    <input type="number" name="quantity" class="form-control me-1" id="quantity" value="1">
+                    <input type="number" name="quantity" class="form-control me-1" id="quantity" value="1" min="1">
                     <div id="quantity"></div>
                 </div>
             </div>