Index: branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_List.php
===================================================================
--- branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_List.php	(revision 18824)
+++ branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_List.php	(revision 18826)
@@ -145,5 +145,4 @@
             $arrErr = $this->lfCheckError($product_id);
             if (count($arrErr) == 0) {
-                $product_class_id = $this->arrForm['product_class_id'];
                 $classcategory_id1 = $this->arrForm['classcategory_id1'];
                 $classcategory_id2 = $this->arrForm['classcategory_id2'];
@@ -156,4 +155,7 @@
                     $classcategory_id2 = '0';
                 }
+                // 規格IDを取得
+                $objProduct = new SC_Product();
+                $product_class_id = $objProduct->getClasscategoryIdsByProductClassId($product_id,$classcategory_id1,$classcategory_id2);
                 $objCartSess = new SC_CartSession();
                 $objCartSess->addProduct(array($product_id, $product_class_id, $classcategory_id1, $classcategory_id2), $this->arrForm['quantity']);
Index: branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_Detail.php
===================================================================
--- branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_Detail.php	(revision 18824)
+++ branches/version-2_5-dev/data/class/pages/products/LC_Page_Products_Detail.php	(revision 18826)
@@ -189,5 +189,4 @@
                 if (count($arrErr) == 0) {
                     $objCartSess = new SC_CartSession();
-                    $product_class_id = $_POST['product_class_id'];
                     $classcategory_id1 = $_POST['classcategory_id1'];
                     $classcategory_id2 = $_POST['classcategory_id2'];
@@ -206,5 +205,7 @@
                         $classcategory_id2 = '0';
                     }
-
+                    // 規格IDを取得
+                    $objProduct = new SC_Product();
+                    $product_class_id = $objProduct->getClasscategoryIdsByProductClassId($_POST['product_id'],$classcategory_id1,$classcategory_id2);
                     $objCartSess->addProduct(array($_POST['product_id'], $product_class_id, $classcategory_id1, $classcategory_id2), $this->objFormParam->getValue('quantity'));
 
Index: branches/version-2_5-dev/data/class/SC_Product.php
===================================================================
--- branches/version-2_5-dev/data/class/SC_Product.php	(revision 18824)
+++ branches/version-2_5-dev/data/class/SC_Product.php	(revision 18826)
@@ -459,4 +459,34 @@
         return $sql;
     }
+
+    /**
+     * 商品規格ID1、2に紐づいた,product_class_idを取得する.
+     *
+     * @param int $productId 商品ID
+     * @param int $classcategory_id1 商品規格ID1
+     * @param int $classcategory_id2 商品規格ID2
+     * @return string product_class_id
+     */
+    function getClasscategoryIdsByProductClassId($productId, $classcategory_id1, $classcategory_id2) {
+        $objQuery = new SC_Query();
+        $col = "T1.product_id AS product_id,T1.product_class_id AS product_class_id,T1.classcategory_id1 AS classcategory_id1,T1.classcategory_id2 AS classcategory_id2";
+        $table = <<< __EOS__
+            (SELECT
+                pc.product_code AS product_code,
+                pc.product_id AS product_id,
+                pc.product_class_id AS product_class_id,
+                pc.class_combination_id AS class_combination_id,
+                COALESCE(cc2.classcategory_id,0) AS classcategory_id1,
+                COALESCE(cc1.classcategory_id,0) AS classcategory_id2
+            FROM
+                dtb_products_class pc LEFT JOIN dtb_class_combination cc1 ON pc.class_combination_id = cc1.class_combination_id
+                LEFT JOIN dtb_class_combination cc2 ON cc1.parent_class_combination_id = cc2.class_combination_id) T1
+__EOS__;
+        $where = "T1.product_id = ? AND T1.classcategory_id1 = ? AND T1.classcategory_id2 = ?";
+        $arrRet = $objQuery->select($col, $table, $where,
+                                    array($productId, $classcategory_id1, $classcategory_id2));
+        return $arrRet[0]['product_class_id'];
+    }
+
 }
 ?>