diff --git a/modules/shop/api_buy.go b/modules/shop/api_buy.go
index 284c890d7..55d2b9eeb 100644
--- a/modules/shop/api_buy.go
+++ b/modules/shop/api_buy.go
@@ -51,7 +51,7 @@ func (this *apiComp) Buy(session comm.IUserSession, req *pb.ShopBuyReq) (code pb
 		need[i] = &cfg.Game_atn{
 			A: v.A,
 			T: v.T,
-			N: int32(math.Ceil(float64(v.N)*float64(conf.Sale)/float64(1000))) * -1,
+			N: int32(math.Ceil(float64(v.N) * float64(conf.Sale) / float64(1000))),
 		}
 	}