diff --git a/code/rest/matter_dao.go b/code/rest/matter_dao.go
index 0394e5f..ab1abab 100644
--- a/code/rest/matter_dao.go
+++ b/code/rest/matter_dao.go
@@ -255,7 +255,17 @@ func (this *MatterDao) FindByUuids(uuids []string, sortArray []builder.OrderPair
 
 	return matters
 }
-func (this *MatterDao) PlainPage(page int, pageSize int, puuid string, userUuid string, name string, dir string, deleted string, extensions []string, sortArray []builder.OrderPair) (int, []*Matter) {
+func (this *MatterDao) PlainPage(
+	page int,
+	pageSize int,
+	puuid string,
+	userUuid string,
+	name string,
+	dir string,
+	deleted string,
+	deleteTimeBefore *time.Time,
+	extensions []string,
+	sortArray []builder.OrderPair) (int, []*Matter) {
 
 	var wp = &builder.WherePair{}
 
@@ -271,6 +281,10 @@ func (this *MatterDao) PlainPage(page int, pageSize int, puuid string, userUuid
 		wp = wp.And(&builder.WherePair{Query: "name LIKE ?", Args: []interface{}{"%" + name + "%"}})
 	}
 
+	if deleteTimeBefore != nil {
+		wp = wp.And(&builder.WherePair{Query: "delete_time < ?", Args: []interface{}{&deleteTimeBefore}})
+	}
+
 	if dir == TRUE {
 		wp = wp.And(&builder.WherePair{Query: "dir = ?", Args: []interface{}{1}})
 	} else if dir == FALSE {
@@ -308,30 +322,40 @@ func (this *MatterDao) PlainPage(page int, pageSize int, puuid string, userUuid
 }
 func (this *MatterDao) Page(page int, pageSize int, puuid string, userUuid string, name string, dir string, deleted string, extensions []string, sortArray []builder.OrderPair) *Pager {
 
-	count, matters := this.PlainPage(page, pageSize, puuid, userUuid, name, dir, deleted, extensions, sortArray)
+	count, matters := this.PlainPage(page, pageSize, puuid, userUuid, name, dir, deleted, nil, extensions, sortArray)
 	pager := NewPager(page, pageSize, count, matters)
 
 	return pager
 }
 
 //handle matter page by page.
-func (this *MatterDao) PageHandle(puuid string, userUuid string, name string, dir string, deleted string, fun func(matter *Matter)) {
+func (this *MatterDao) PageHandle(
+	puuid string,
+	userUuid string,
+	name string,
+	dir string,
+	deleted string,
+	deleteTimeBefore *time.Time,
+	sortArray []builder.OrderPair,
+	fun func(matter *Matter)) {
 
-	//delete share and bridges.
 	pageSize := 1000
-	sortArray := []builder.OrderPair{
-		{
-			Key:   "uuid",
-			Value: DIRECTION_ASC,
-		},
+	if sortArray == nil || len(sortArray) == 0 {
+		sortArray = []builder.OrderPair{
+			{
+				Key:   "uuid",
+				Value: DIRECTION_ASC,
+			},
+		}
 	}
-	count, _ := this.PlainPage(0, pageSize, puuid, userUuid, name, dir, deleted, nil, sortArray)
+
+	count, _ := this.PlainPage(0, pageSize, puuid, userUuid, name, dir, deleted, deleteTimeBefore, nil, sortArray)
 	if count > 0 {
 		var totalPages = int(math.Ceil(float64(count) / float64(pageSize)))
 
 		var page int
 		for page = 0; page < totalPages; page++ {
-			_, matters := this.PlainPage(0, pageSize, puuid, userUuid, name, dir, deleted, nil, sortArray)
+			_, matters := this.PlainPage(0, pageSize, puuid, userUuid, name, dir, deleted, deleteTimeBefore, nil, sortArray)
 			for _, matter := range matters {
 				fun(matter)
 			}
diff --git a/code/rest/matter_service.go b/code/rest/matter_service.go
index 09b32e9..76a9a56 100644
--- a/code/rest/matter_service.go
+++ b/code/rest/matter_service.go
@@ -4,6 +4,7 @@ import (
 	"archive/zip"
 	"fmt"
 	"github.com/eyebluecn/tank/code/core"
+	"github.com/eyebluecn/tank/code/tool/builder"
 	"github.com/eyebluecn/tank/code/tool/download"
 	"github.com/eyebluecn/tank/code/tool/i18n"
 	"github.com/eyebluecn/tank/code/tool/result"
@@ -1151,7 +1152,7 @@ func (this *MatterService) DeleteByPhysics(request *http.Request, user *User) {
 func (this *MatterService) deleteFolderByPhysics(request *http.Request, dirMatter *Matter, user *User) {
 
 	//scan user's file. scan level by level.
-	this.matterDao.PageHandle(dirMatter.Uuid, user.Uuid, "", "", "", func(matter *Matter) {
+	this.matterDao.PageHandle(dirMatter.Uuid, user.Uuid, "", "", "", nil, nil, func(matter *Matter) {
 
 		if matter.Dir {
 			//delete children first.
@@ -1195,7 +1196,7 @@ func (this *MatterService) scanPhysicsFolder(request *http.Request, dirInfo os.F
 	}
 
 	//fetch all matters under this folder.
-	_, matters := this.matterDao.PlainPage(0, 1000, dirMatter.Uuid, user.Uuid, "", "", "", nil, nil)
+	_, matters := this.matterDao.PlainPage(0, 1000, dirMatter.Uuid, user.Uuid, "", "", "", nil, nil, nil)
 	nameMatterMap := make(map[string]*Matter)
 	for _, m := range matters {
 		nameMatterMap[m.Name] = m
@@ -1255,3 +1256,39 @@ func (this *MatterService) scanPhysicsFolder(request *http.Request, dirInfo os.F
 		}
 	}
 }
+
+//clean all the expired deleted matters
+func (this *MatterService) CleanExpiredDeletedMatters() {
+	//mock a request.
+	request := &http.Request{}
+
+	preference := this.preferenceService.Fetch()
+
+	this.userDao.PageHandle("", "", func(user *User) {
+
+		this.logger.Info("Clean %s 's deleted matters", user.Username)
+
+		thenDate := time.Now()
+		thenDate = thenDate.AddDate(0, 0, int(-preference.DeletedKeepDays))
+		thenDate = util.FirstSecondOfDay(thenDate)
+
+		//first remove all the matter(not dir).
+		this.matterDao.PageHandle("", "", "", FALSE, TRUE, &thenDate, nil, func(matter *Matter) {
+			this.Delete(request, matter, user)
+		})
+
+		sortArray := []builder.OrderPair{
+			{
+				Key:   "path",
+				Value: DIRECTION_DESC,
+			},
+		}
+
+		//remove all the deleted directories. sort by path.
+		this.matterDao.PageHandle("", "", "", TRUE, TRUE, &thenDate, sortArray, func(matter *Matter) {
+			this.Delete(request, matter, user)
+		})
+
+	})
+
+}
diff --git a/code/rest/task_service.go b/code/rest/task_service.go
index 8d002e3..ffaf9d6 100644
--- a/code/rest/task_service.go
+++ b/code/rest/task_service.go
@@ -58,11 +58,11 @@ func (this *TaskService) InitCleanFootprintTask() {
 	//use standard cron expression. 5 fields. ()
 	expression := "10 0 * * *"
 	cronJob := cron.New()
-	entryId, err := cronJob.AddFunc(expression, this.footprintService.CleanOldData)
+	_, err := cronJob.AddFunc(expression, this.footprintService.CleanOldData)
 	core.PanicError(err)
 	cronJob.Start()
 
-	this.logger.Info("[cron job] Every day 00:10 delete Footprint data of 8 days ago. entryId = %d", entryId)
+	this.logger.Info("[cron job] Every day 00:10 delete Footprint data of 8 days ago.")
 }
 
 //init the elt task.
@@ -70,11 +70,23 @@ func (this *TaskService) InitEtlTask() {
 
 	expression := "5 0 * * *"
 	cronJob := cron.New()
-	entryId, err := cronJob.AddFunc(expression, this.dashboardService.Etl)
+	_, err := cronJob.AddFunc(expression, this.dashboardService.Etl)
 	core.PanicError(err)
 	cronJob.Start()
 
-	this.logger.Info("[cron job] Everyday 00:05 ETL dashboard data. entryId = %d", entryId)
+	this.logger.Info("[cron job] Everyday 00:05 ETL dashboard data.")
+}
+
+//init the clean deleted matters task.
+func (this *TaskService) InitCleanDeletedMattersTask() {
+
+	expression := "0 1 * * *"
+	cronJob := cron.New()
+	_, err := cronJob.AddFunc(expression, this.matterService.CleanExpiredDeletedMatters)
+	core.PanicError(err)
+	cronJob.Start()
+
+	this.logger.Info("[cron job] Everyday 01:00 Clean deleted matters.")
 }
 
 //scan task.
@@ -165,11 +177,11 @@ func (this *TaskService) InitScanTask() {
 	}
 
 	this.scanTaskCron = cron.New()
-	entryId, err := this.scanTaskCron.AddFunc(scanConfig.Cron, this.doScanTask)
+	_, err := this.scanTaskCron.AddFunc(scanConfig.Cron, this.doScanTask)
 	core.PanicError(err)
 	this.scanTaskCron.Start()
 
-	this.logger.Info("[cron job] %s do scan task. entryId = %d", scanConfig.Cron, entryId)
+	this.logger.Info("[cron job] %s do scan task.", scanConfig.Cron)
 }
 
 func (this *TaskService) Bootstrap() {
@@ -180,6 +192,9 @@ func (this *TaskService) Bootstrap() {
 	//load the etl task.
 	this.InitEtlTask()
 
+	//load the clean deleted matters task.
+	this.InitCleanDeletedMattersTask()
+
 	//load the scan task.
 	this.InitScanTask()
 
diff --git a/code/support/tank_logger.go b/code/support/tank_logger.go
index c5c4fbd..a4d2a3c 100644
--- a/code/support/tank_logger.go
+++ b/code/support/tank_logger.go
@@ -27,11 +27,11 @@ func (this *TankLogger) Init() {
 
 	expression := "0 0 * * *"
 	cronJob := cron.New()
-	entryId, err := cronJob.AddFunc(expression, this.maintain)
+	_, err := cronJob.AddFunc(expression, this.maintain)
 	core.PanicError(err)
 	cronJob.Start()
 
-	this.Info("[cron job] Every day 00:00 maintain log file. entryId = %d", entryId)
+	this.Info("[cron job] Every day 00:00 maintain log file.")
 }
 
 func (this *TankLogger) Destroy() {