diff --git a/pkg/compute/guestdrivers/qcloud.go b/pkg/compute/guestdrivers/qcloud.go
index 5090af0b30..e816c9e248 100644
--- a/pkg/compute/guestdrivers/qcloud.go
+++ b/pkg/compute/guestdrivers/qcloud.go
@@ -102,16 +102,12 @@ func (self *SQcloudGuestDriver) ValidateCreateData(ctx context.Context, userCred
 	}
 	switch sysDisk.Backend {
 	case models.STORAGE_CLOUD_BASIC, models.STORAGE_CLOUD_SSD:
-		if sysDisk.SizeMb < 50*10024 || sysDisk.SizeMb > 500*1024 {
-			return nil, fmt.Errorf("The %s system disk size must be in the range of 50 ~ 500GB", sysDisk.Backend)
+		if sysDisk.SizeMb > 500*1024 {
+			return nil, fmt.Errorf("The %s system disk size must be less than 500GB", sysDisk.Backend)
 		}
 	case models.STORAGE_CLOUD_PREMIUM:
-		if sysDisk.SizeMb < 50*1024 || sysDisk.SizeMb > 1024*1024 {
-			return nil, fmt.Errorf("The %s system disk size must be in the range of 50 ~ 1024GB", sysDisk.Backend)
-		}
-	default:
-		if sysDisk.SizeMb < 50*1024 {
-			return nil, fmt.Errorf("The system disk must be greater than or equal to 50GB")
+		if sysDisk.SizeMb > 1024*1024 {
+			return nil, fmt.Errorf("The %s system disk size must be less than 1024GB", sysDisk.Backend)
 		}
 	}
 	return data, nil