diff --git a/webapp/services/RoomBattleDataService.php b/webapp/services/RoomBattleDataService.php
index f468c585..48901d92 100644
--- a/webapp/services/RoomBattleDataService.php
+++ b/webapp/services/RoomBattleDataService.php
@@ -339,8 +339,8 @@ class RoomBattleDataService extends BaseService {
             for ($i = 0; $i < $member['box_num']; ++$i) {
                 $rand = $rate * 100;
                 $rnd = rand(1,100);
+                ++$realBoxNum;
                 if ($rnd <= $rand){
-                    ++$realBoxNum;
                     $chestItems = LootService::dropOutItem($rewardMeta['chestLoot']);
                     if (count($chestItems)>0){
                         $event = array(