diff --git a/clone/clone_test.go b/clone/clone_test.go
index 0ba4786..bf51b23 100644
--- a/clone/clone_test.go
+++ b/clone/clone_test.go
@@ -61,12 +61,12 @@ func TestCloneCommand_MultipleProjects(t *testing.T) {
 		if len(db.Repositories) != 4 {
 			t.Fatal("helloworld and fibonacci were not registered.")
 		}
-		var hwRepo = db.Repositories[1]
-		if message := validate(hwRepo, "helloworld", "../testdata/hoge/helloworld"); message != "" {
+		var hwRepo = db.FindRepository("helloworld")
+		if message := validate(*hwRepo, "helloworld", "../testdata/hoge/helloworld"); message != "" {
 			t.Error(message)
 		}
-		var fiboRepo = db.Repositories[0]
-		if message := validate(fiboRepo, "fibonacci", "../testdata/hoge/fibonacci"); message != "" {
+		var fiboRepo = db.FindRepository("fibonacci")
+		if message := validate(*fiboRepo, "fibonacci", "../testdata/hoge/fibonacci"); message != "" {
 			t.Error(message)
 		}
 		if !db.HasGroup("not-exist-group") || len(db.Groups) != 3 {
@@ -92,8 +92,8 @@ func TestCloneCommand_Run(t *testing.T) {
 		if len(db.Repositories) != 3 {
 			t.Fatal("helloworld was not registered.")
 		}
-		var repo = db.Repositories[0]
-		if message := validate(repo, "helloworld", "./helloworld"); message != "" {
+		var repo = db.FindRepository("helloworld")
+		if message := validate(*repo, "helloworld", "./helloworld"); message != "" {
 			t.Error(message)
 		}
 		if db.ContainsCount("no-group") != 1 || !db.HasRelation("no-group", "helloworld") {
@@ -115,8 +115,8 @@ func TestCloneCommand_SpecifyingId(t *testing.T) {
 		if len(db.Repositories) != 3 {
 			t.Fatal("newid was not registered.")
 		}
-		var repo = db.Repositories[0]
-		if message := validate(repo, "newid", "../testdata/newid"); message != "" {
+		var repo = db.FindRepository("newid")
+		if message := validate(*repo, "newid", "../testdata/newid"); message != "" {
 			t.Error(message)
 		}
 	})
diff --git a/common/config.go b/common/config.go
index 12b7b7b..929f6c7 100644
--- a/common/config.go
+++ b/common/config.go
@@ -19,6 +19,7 @@ const (
 	RrhAutoDeleteGroup  = "RRH_AUTO_DELETE_GROUP"
 	RrhAutoCreateGroup  = "RRH_AUTO_CREATE_GROUP"
 	RrhTimeFormat       = "RRH_TIME_FORMAT"
+	RrhSortOnUpdating   = "RRH_SORT_ON_UPDATING"
 )
 
 const (
@@ -45,6 +46,7 @@ type Config struct {
 	DefaultGroupName string `json:"rrh_default_group_name"`
 	TimeFormat       string `json:"rrh_time_format"`
 	OnError          string `json:"rrh_on_error"`
+	SortOnUpdating   string `json:"rrh_sort_on_updating"`
 }
 
 func trueOrFalse(value string) (string, error) {
@@ -78,6 +80,12 @@ func (config *Config) Update(label string, value string) error {
 			config.AutoCreateGroup = flag
 		}
 		return err
+	case RrhSortOnUpdating:
+		var flag, err = trueOrFalse(value)
+		if err == nil {
+			config.SortOnUpdating = flag
+		}
+		return err
 	case RrhHome:
 		config.Home = value
 		return nil
@@ -118,6 +126,8 @@ func (config *Config) GetString(label string) (value string, readFrom string) {
 		return config.getStringFromEnv(RrhAutoDeleteGroup, config.AutoDeleteGroup)
 	case RrhAutoCreateGroup:
 		return config.getStringFromEnv(RrhAutoCreateGroup, config.AutoCreateGroup)
+	case RrhSortOnUpdating:
+		return config.getStringFromEnv(RrhSortOnUpdating, config.SortOnUpdating)
 	case RrhHome:
 		return config.getStringFromEnv(RrhHome, config.Home)
 	case RrhConfigPath:
@@ -164,6 +174,8 @@ func (config *Config) findDefaultValue(label string) (value string, readFrom str
 		return "false", Default
 	case RrhAutoCreateGroup:
 		return "false", Default
+	case RrhSortOnUpdating:
+		return "false", Default
 	default:
 		return "", NotFound
 	}
diff --git a/common/config_cmd.go b/common/config_cmd.go
index 91ae1c0..b85ce2a 100644
--- a/common/config_cmd.go
+++ b/common/config_cmd.go
@@ -145,6 +145,7 @@ func (clc *configListCommand) Run(args []string) int {
 	fmt.Println(config.formatVariableAndValue(RrhTimeFormat))
 	fmt.Println(config.formatVariableAndValue(RrhAutoCreateGroup))
 	fmt.Println(config.formatVariableAndValue(RrhAutoDeleteGroup))
+	fmt.Println(config.formatVariableAndValue(RrhSortOnUpdating))
 	return 0
 }
 
diff --git a/common/config_test.go b/common/config_test.go
index 92f99ed..1586177 100644
--- a/common/config_test.go
+++ b/common/config_test.go
@@ -92,6 +92,7 @@ func ExampleConfigCommand_Run() {
 	// RRH_TIME_FORMAT: relative (default)
 	// RRH_AUTO_CREATE_GROUP: true (config_file)
 	// RRH_AUTO_DELETE_GROUP: false (config_file)
+	// RRH_SORT_ON_UPDATING: true (config_file)
 }
 func Example_configListCommand_Run() {
 	os.Setenv(RrhConfigPath, "../testdata/config.json")
@@ -107,6 +108,7 @@ func Example_configListCommand_Run() {
 	// RRH_TIME_FORMAT: relative (default)
 	// RRH_AUTO_CREATE_GROUP: true (config_file)
 	// RRH_AUTO_DELETE_GROUP: false (config_file)
+	// RRH_SORT_ON_UPDATING: true (config_file)
 }
 
 func TestOpenConfigBrokenJson(t *testing.T) {
diff --git a/common/database.go b/common/database.go
index c1e1f22..715e739 100644
--- a/common/database.go
+++ b/common/database.go
@@ -137,6 +137,23 @@ func (db *Database) FindGroup(groupID string) *Group {
 	return nil
 }
 
+func sortIfNeeded(db *Database) {
+	if db.Config.GetValue(RrhSortOnUpdating) == "yes" {
+		sort.Slice(db.Repositories, func(i, j int) bool {
+			return db.Repositories[i].ID < db.Repositories[j].ID
+		})
+		sort.Slice(db.Groups, func(i, j int) bool {
+			return db.Groups[i].Name < db.Groups[j].Name
+		})
+		sort.Slice(db.Relations, func(i, j int) bool {
+			if db.Relations[i].GroupName == db.Relations[j].GroupName {
+				return db.Relations[i].RepositoryID < db.Relations[j].RepositoryID
+			}
+			return db.Relations[i].GroupName < db.Relations[j].GroupName
+		})
+	}
+}
+
 /*
 CreateRepository returns the repository by creating the given parameters and store it to database.
 */
@@ -146,9 +163,7 @@ func (db *Database) CreateRepository(repoID string, path string, remotes []Remot
 	}
 	var repo = Repository{repoID, path, remotes}
 	db.Repositories = append(db.Repositories, repo)
-	sort.Slice(db.Repositories, func(i, j int) bool {
-		return db.Repositories[i].ID < db.Repositories[j].ID
-	})
+	sortIfNeeded(db)
 
 	return &repo, nil
 }
@@ -162,10 +177,7 @@ func (db *Database) CreateGroup(groupID string, description string) (*Group, err
 	}
 	var group = Group{groupID, description}
 	db.Groups = append(db.Groups, group)
-
-	sort.Slice(db.Groups, func(i, j int) bool {
-		return db.Groups[i].Name < db.Groups[j].Name
-	})
+	sortIfNeeded(db)
 
 	return &group, nil
 }
@@ -184,9 +196,7 @@ func (db *Database) UpdateGroup(groupID string, newGroupID string, newDescriptio
 			db.Groups[i].Description = newDescription
 		}
 	}
-	sort.Slice(db.Groups, func(i, j int) bool {
-		return db.Groups[i].Name < db.Groups[j].Name
-	})
+	sortIfNeeded(db)
 
 	return true
 }
@@ -201,9 +211,7 @@ func (db *Database) Relate(groupID string, repoID string) error {
 		return nil
 	}
 	db.Relations = append(db.Relations, Relation{repoID, groupID})
-	sort.Slice(db.Relations, func(i, j int) bool {
-		return db.Relations[i].GroupName < db.Relations[j].GroupName
-	})
+	sortIfNeeded(db)
 
 	return nil
 }
@@ -329,7 +337,7 @@ func (db *Database) DeleteRepository(repoID string) error {
 	return nil
 }
 
-func (db *Database) deleteGroup(groupID string) error {
+func deleteGroup(db *Database, groupID string) error {
 	var groups = []Group{}
 	for _, group := range db.Groups {
 		if group.Name != groupID {
@@ -353,7 +361,7 @@ func (db *Database) DeleteGroup(groupID string) error {
 	if groups[groupID] != 0 {
 		return fmt.Errorf("%s: group has %d relatins", groupID, groups[groupID])
 	}
-	return db.deleteGroup(groupID)
+	return deleteGroup(db, groupID)
 }
 
 /*
@@ -365,7 +373,7 @@ func (db *Database) ForceDeleteGroup(groupID string) error {
 		return fmt.Errorf("%s: group not found", groupID)
 	}
 	db.UnrelateFromGroup(groupID)
-	return db.deleteGroup(groupID)
+	return deleteGroup(db, groupID)
 }
 
 func databasePath(config *Config) string {
diff --git a/remove/remove_test.go b/remove/remove_test.go
index f163e1e..18ebdf9 100644
--- a/remove/remove_test.go
+++ b/remove/remove_test.go
@@ -44,9 +44,9 @@ func TestRemoveRepository(t *testing.T) {
 	if err := rm.executeRemoveRepository(db, "unknown-repo"); err == nil {
 		t.Error("unknown-repo: found")
 	}
-	var _ = rm.executeRemoveRepository(db, "repo1")
-	if len(db.Repositories) != 1 {
-		t.Error("repo1 did not remove?")
+	var err = rm.executeRemoveRepository(db, "repo1")
+	if err != nil || len(db.Repositories) != 1 {
+		t.Errorf("repo1 did not remove?: %s", err.Error())
 	}
 	if len(db.Groups) != 2 {
 		t.Error("the number of groups changed")