diff --git a/weed/command/master.go b/weed/command/master.go
index 8e10d25a2..acfa9484a 100644
--- a/weed/command/master.go
+++ b/weed/command/master.go
@@ -49,21 +49,22 @@ type MasterOptions struct {
 	volumePreallocate          *bool
 	maxParallelVacuumPerServer *int
 	// pulseSeconds       *int
-	defaultReplication *string
-	garbageThreshold   *float64
-	whiteList          *string
-	disableHttp        *bool
-	metricsAddress     *string
-	metricsIntervalSec *int
-	raftResumeState    *bool
-	metricsHttpPort    *int
-	metricsHttpIp      *string
-	heartbeatInterval  *time.Duration
-	electionTimeout    *time.Duration
-	raftHashicorp      *bool
-	raftBootstrap      *bool
-	telemetryUrl       *string
-	telemetryEnabled   *bool
+	defaultReplication     *string
+	garbageThreshold       *float64
+	whiteList              *string
+	disableHttp            *bool
+	metricsAddress         *string
+	metricsIntervalSec     *int
+	raftResumeState        *bool
+	metricsHttpPort        *int
+	metricsHttpIp          *string
+	heartbeatInterval      *time.Duration
+	electionTimeout        *time.Duration
+	raftHashicorp          *bool
+	raftBootstrap          *bool
+	telemetryUrl           *string
+	telemetryEnabled       *bool
+	intervalToCollectStats *time.Duration
 }
 
 func init() {
@@ -93,6 +94,7 @@ func init() {
 	m.raftBootstrap = cmdMaster.Flag.Bool("raftBootstrap", false, "Whether to bootstrap the Raft cluster")
 	m.telemetryUrl = cmdMaster.Flag.String("telemetry.url", "https://telemetry.seaweedfs.com/api/collect", "telemetry server URL to send usage statistics")
 	m.telemetryEnabled = cmdMaster.Flag.Bool("telemetry", false, "enable telemetry reporting")
+	m.intervalToCollectStats = cmdMaster.Flag.Duration("intervalToCollectStats", time.Second*120, "interval to collect s3 stats")
 }
 
 var cmdMaster = &Command{
@@ -244,6 +246,7 @@ func startMaster(masterOption MasterOptions, masterWhiteList []string) {
 	}
 
 	go ms.MasterClient.KeepConnectedToMaster(context.Background())
+	go weed_server.CollectCollectionsStats(context.Background(), ms, *masterOption.intervalToCollectStats)
 
 	// start http server
 	var (
diff --git a/weed/command/server.go b/weed/command/server.go
index 0ad126dbb..09eda86c7 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -108,6 +108,7 @@ func init() {
 	masterOptions.electionTimeout = cmdServer.Flag.Duration("master.electionTimeout", 10*time.Second, "election timeout of master servers")
 	masterOptions.telemetryUrl = cmdServer.Flag.String("master.telemetry.url", "https://telemetry.seaweedfs.com/api/collect", "telemetry server URL to send usage statistics")
 	masterOptions.telemetryEnabled = cmdServer.Flag.Bool("master.telemetry", false, "enable telemetry reporting")
+	masterOptions.intervalToCollectStats = cmdServer.Flag.Duration("master.intervalToCollectStats", time.Second*120, "interval to collect s3 stats")
 
 	filerOptions.filerGroup = cmdServer.Flag.String("filer.filerGroup", "", "share metadata with other filers in the same filerGroup")
 	filerOptions.collection = cmdServer.Flag.String("filer.collection", "", "all data will be stored in this collection")
diff --git a/weed/server/master_server.go b/weed/server/master_server.go
index bd83d5a96..9a095a303 100644
--- a/weed/server/master_server.go
+++ b/weed/server/master_server.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/seaweedfs/seaweedfs/weed/stats"
+	"github.com/seaweedfs/seaweedfs/weed/storage/super_block"
 	"github.com/seaweedfs/seaweedfs/weed/telemetry"
 
 	"github.com/seaweedfs/seaweedfs/weed/cluster"
@@ -57,7 +58,7 @@ type MasterOption struct {
 	IsFollower              bool
 	TelemetryUrl            string
 	TelemetryEnabled        bool
-	VolumeGrowthDisabled      bool
+	VolumeGrowthDisabled    bool
 }
 
 type MasterServer struct {
@@ -434,3 +435,50 @@ func (ms *MasterServer) Reload() {
 		util.StringSplit(v.GetString("guard.white_list"), ",")...),
 	)
 }
+
+func CollectCollectionsStats(ctx context.Context, ms *MasterServer, intervalToCollect time.Duration) {
+	ticker := time.NewTicker(intervalToCollect)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			volumeList, err := ms.VolumeList(context.Background(), &master_pb.VolumeListRequest{})
+			if err != nil {
+				glog.Errorf("collect volume list: %v", err)
+			}
+
+			collectionInfos := make(map[string]*shell.CollectionInfo)
+			for _, dc := range volumeList.TopologyInfo.DataCenterInfos {
+				for _, r := range dc.RackInfos {
+					for _, dn := range r.DataNodeInfos {
+						for _, diskInfo := range dn.DiskInfos {
+							for _, vif := range diskInfo.VolumeInfos {
+								c := vif.Collection
+								cif, found := collectionInfos[c]
+								if !found {
+									cif = &shell.CollectionInfo{}
+									collectionInfos[c] = cif
+								}
+								replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(vif.ReplicaPlacement))
+								copyCount := float64(replicaPlacement.GetCopyCount())
+								cif.Size += float64(vif.Size) / copyCount
+								cif.DeleteCount += float64(vif.DeleteCount) / copyCount
+								cif.FileCount += float64(vif.FileCount) / copyCount
+								cif.DeletedByteCount += float64(vif.DeletedByteCount) / copyCount
+								cif.VolumeCount++
+							}
+						}
+					}
+				}
+			}
+
+			for k, v := range collectionInfos {
+				stats.S3BucketFileCount.WithLabelValues(k).Set(v.FileCount - v.DeleteCount)
+				stats.S3BucketSize.WithLabelValues(k).Set(v.Size - v.DeletedByteCount)
+			}
+		}
+	}
+}
diff --git a/weed/stats/metrics.go b/weed/stats/metrics.go
index 2723e253f..1af98b51f 100644
--- a/weed/stats/metrics.go
+++ b/weed/stats/metrics.go
@@ -382,6 +382,22 @@ var (
 			Name:      "uploaded_objects",
 			Help:      "Number of objects uploaded in each bucket.",
 		}, []string{"bucket"})
+
+	S3BucketFileCount = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: Namespace,
+			Subsystem: "s3",
+			Name:      "bucket_file_count",
+			Help:      "Number files in bucket",
+		}, []string{"bucket"})
+
+	S3BucketSize = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: Namespace,
+			Subsystem: "s3",
+			Name:      "bucket_size",
+			Help:      "Bucket size in bytes",
+		}, []string{"bucket"})
 )
 
 func init() {
@@ -433,6 +449,8 @@ func init() {
 	Gather.MustRegister(S3BucketTrafficSentBytesCounter)
 	Gather.MustRegister(S3DeletedObjectsCounter)
 	Gather.MustRegister(S3UploadedObjectsCounter)
+	Gather.MustRegister(S3BucketFileCount)
+	Gather.MustRegister(S3BucketSize)
 
 	go bucketMetricTTLControl()
 }