diff --git a/pkg/apis/compute/instance_snapshot.go b/pkg/apis/compute/instance_snapshot.go
index 7456f8641a..022838fa93 100644
--- a/pkg/apis/compute/instance_snapshot.go
+++ b/pkg/apis/compute/instance_snapshot.go
@@ -27,6 +27,8 @@ type SimpleSnapshot struct {
 	DiskType string `json:"disk_type"`
 	// 区域Id
 	CloudregionId string `json:"cloudregion_id"`
+	// 快照大小
+	Size int `json:"size"`
 }
 
 type InstnaceSnapshotDetails struct {
diff --git a/pkg/compute/models/guest_actions.go b/pkg/compute/models/guest_actions.go
index a862793d3f..34c699a6a5 100644
--- a/pkg/compute/models/guest_actions.go
+++ b/pkg/compute/models/guest_actions.go
@@ -3479,20 +3479,37 @@ func (self *SGuest) PerformPostpaidExpire(ctx context.Context, userCred mcclient
 		return nil, httperrors.NewBadRequestError("guest billing type is %s", self.BillingType)
 	}
 
-	durationStr := jsonutils.GetAnyString(data, []string{"duration"})
-	if len(durationStr) == 0 {
-		return nil, httperrors.NewInputParameterError("missong duration")
-	}
-
-	bc, err := billing.ParseBillingCycle(durationStr)
-	if err != nil {
-		return nil, httperrors.NewInputParameterError("invalid duration %s: %s", durationStr, err)
-	}
-
 	if !self.GetDriver().IsSupportPostpaidExpire() {
 		return nil, httperrors.NewBadRequestError("guest %s unsupport postpaid expire", self.Hypervisor)
 	}
 
+	var (
+		bc          billing.SBillingCycle
+		err         error
+		durationStr string
+	)
+	durationStr, _ = data.GetString("duration")
+	if len(durationStr) == 0 {
+		expireTime, err := data.GetTime("expire_time")
+		if err != nil {
+			return nil, httperrors.NewInputParameterError("missing duration/expire_time")
+		}
+		timeC := self.ExpiredAt
+		if timeC.IsZero() {
+			timeC = time.Now()
+		}
+		dur := expireTime.Sub(timeC)
+		if dur <= 0 {
+			return nil, httperrors.NewInputParameterError("expire time is before current expire at")
+		}
+		bc = billing.DurationToBillingCycle(dur)
+	} else {
+		bc, err = billing.ParseBillingCycle(durationStr)
+		if err != nil {
+			return nil, httperrors.NewInputParameterError("invalid duration %s: %s", durationStr, err)
+		}
+	}
+
 	err = self.SaveRenewInfo(ctx, userCred, &bc, nil, billing_api.BILLING_TYPE_POSTPAID)
 	return nil, err
 }
@@ -3502,7 +3519,7 @@ func (self *SGuest) AllowPerformRenew(ctx context.Context, userCred mcclient.Tok
 }
 
 func (self *SGuest) PerformRenew(ctx context.Context, userCred mcclient.TokenCredential, query jsonutils.JSONObject, data jsonutils.JSONObject) (jsonutils.JSONObject, error) {
-	durationStr := jsonutils.GetAnyString(data, []string{"duration"})
+	durationStr, _ := data.GetString("duration")
 	if len(durationStr) == 0 {
 		return nil, httperrors.NewInputParameterError("missong duration")
 	}
diff --git a/pkg/compute/models/instance_snapshots.go b/pkg/compute/models/instance_snapshots.go
index 6d6cf60c53..edc9636c1a 100644
--- a/pkg/compute/models/instance_snapshots.go
+++ b/pkg/compute/models/instance_snapshots.go
@@ -124,6 +124,7 @@ func (self *SInstanceSnapshot) getMoreDetails(userCred mcclient.TokenCredential,
 			StorageId:     snapshots[i].StorageId,
 			DiskType:      snapshots[i].DiskType,
 			CloudregionId: snapshots[i].CloudregionId,
+			Size:          snapshots[i].Size,
 		})
 
 		if len(snapshots[i].StorageId) > 0 {
diff --git a/pkg/util/billing/billingcycle.go b/pkg/util/billing/billingcycle.go
index e51841dfb3..3511a5470e 100644
--- a/pkg/util/billing/billingcycle.go
+++ b/pkg/util/billing/billingcycle.go
@@ -37,6 +37,7 @@ const (
 
 var (
 	ErrInvalidBillingCycle = errors.New("invalid billing cycle")
+	ErrInvalidDuration     = errors.New("invalid duration")
 )
 
 type SBillingCycle struct {
@@ -74,6 +75,14 @@ func ParseBillingCycle(cycleStr string) (SBillingCycle, error) {
 	return cycle, nil
 }
 
+// parse duration to minute unit billing cycle
+func DurationToBillingCycle(dur time.Duration) SBillingCycle {
+	return SBillingCycle{
+		Unit:  BillingCycleMinute,
+		Count: int(dur.Minutes()),
+	}
+}
+
 func (cycle *SBillingCycle) String() string {
 	return fmt.Sprintf("%d%s", cycle.Count, cycle.Unit)
 }