diff --git a/webapp/controller/MarketController.class.php b/webapp/controller/MarketController.class.php
index b111e4e1..4f6373f3 100644
--- a/webapp/controller/MarketController.class.php
+++ b/webapp/controller/MarketController.class.php
@@ -37,6 +37,19 @@ class MarketController extends BaseController {
 
     public function prebuy()
     {
+        $account = getReqVal('account', '');
+        $goodsId = getReqVal('goods_id', '');
+
+        $goodsMeta = mt\Market::get($goodsId);
+        if (!$goodsMeta) {
+            $this->_rspErr(1, 'config error');
+            return;
+        }
+        $inventory = Goods::getRemainBuyableNum($meta);
+        if ($inventory < 0) {
+            $this->_rspErr(2, 'insufficient inventory');
+            return;
+        }
     }
 
     public function sell()
@@ -88,7 +101,7 @@ class MarketController extends BaseController {
         $nft['type'] = 0;
         $nft['token_id'] = '';
         $nft['status'] = 0;
-        $nft['inventory'] = 0;
+        $nft['inventory'] = $inventory;
         $nft['owner_address'] = '';
         $nft['owner_id'] = '';
         $nft['image_avatar'] = '';