diff --git a/server/gameserver/boxdrop.cc b/server/gameserver/boxdrop.cc
index 378aae05..11030e71 100644
--- a/server/gameserver/boxdrop.cc
+++ b/server/gameserver/boxdrop.cc
@@ -288,5 +288,13 @@ int BoxDrop::GetAndDecObjBoxNum(int uniid)
 
 int BoxDrop::GetUsedBoxNum()
 {
-    return 0;
+    int num = 0;
+    room_->TraverseHumanList
+        (
+         [&num] (Human* hum) -> bool
+         {
+             num += hum->box_num;
+             return true;
+         });
+    return num;
 }