diff --git a/code/client/global/conf.go b/code/client/global/conf.go
index 0dd31a9..354dc0a 100644
--- a/code/client/global/conf.go
+++ b/code/client/global/conf.go
@@ -2,6 +2,7 @@ package global
 
 import (
 	"crypto/md5"
+	"natpass/code/utils"
 	"os"
 
 	"github.com/lwch/runtime"
@@ -23,7 +24,7 @@ type Configure struct {
 	Server    string
 	Enc       [md5.Size]byte
 	LogDir    string
-	LogSize   int
+	LogSize   utils.Bytes
 	LogRotate int
 	Tunnels   []Tunnel
 }
@@ -34,9 +35,9 @@ func LoadConf(dir string) *Configure {
 		Server string `yaml:"server"`
 		Secret string `yaml:"secret"`
 		Log    struct {
-			Dir    string `yaml:"dir"`
-			Size   int    `yaml:"size"`
-			Rotate int    `yaml:"rotate"`
+			Dir    string      `yaml:"dir"`
+			Size   utils.Bytes `yaml:"size"`
+			Rotate int         `yaml:"rotate"`
 		} `yaml:"log"`
 		Tunnel []Tunnel `yaml:"tunnel"`
 	}
diff --git a/code/client/main.go b/code/client/main.go
index c4526a6..212676f 100644
--- a/code/client/main.go
+++ b/code/client/main.go
@@ -33,7 +33,7 @@ func main() {
 
 	cfg := global.LoadConf(*conf)
 
-	logging.SetSizeRotate(cfg.LogDir, "np-cli", cfg.LogSize, cfg.LogRotate, true)
+	logging.SetSizeRotate(cfg.LogDir, "np-cli", int(cfg.LogSize.Bytes()), cfg.LogRotate, true)
 
 	conn, err := tls.Dial("tcp", cfg.Server, nil)
 	runtime.Assert(err)
diff --git a/code/server/global/conf.go b/code/server/global/conf.go
index 1787697..0a4edc5 100644
--- a/code/server/global/conf.go
+++ b/code/server/global/conf.go
@@ -2,6 +2,7 @@ package global
 
 import (
 	"crypto/md5"
+	"natpass/code/utils"
 	"os"
 
 	"github.com/lwch/runtime"
@@ -14,7 +15,7 @@ type Configure struct {
 	TLSKey    string
 	TLSCrt    string
 	LogDir    string
-	LogSize   int
+	LogSize   utils.Bytes
 	LogRotate int
 }
 
@@ -23,9 +24,9 @@ func LoadConf(dir string) *Configure {
 		Listen uint16 `yaml:"listen"`
 		Secret string `yaml:"secret"`
 		Log    struct {
-			Dir    string `yaml:"dir"`
-			Size   int    `yaml:"size"`
-			Rotate int    `yaml:"rotate"`
+			Dir    string      `yaml:"dir"`
+			Size   utils.Bytes `yaml:"size"`
+			Rotate int         `yaml:"rotate"`
 		} `yaml:"log"`
 		TLS struct {
 			Key string `yaml:"key"`
diff --git a/code/server/main.go b/code/server/main.go
index 325679e..83d66fe 100644
--- a/code/server/main.go
+++ b/code/server/main.go
@@ -31,7 +31,7 @@ func main() {
 
 	cfg := global.LoadConf(*conf)
 
-	logging.SetSizeRotate(cfg.LogDir, "np-svr", cfg.LogSize, cfg.LogRotate, true)
+	logging.SetSizeRotate(cfg.LogDir, "np-svr", int(cfg.LogSize.Bytes()), cfg.LogRotate, true)
 
 	cert, err := tls.LoadX509KeyPair(cfg.TLSCrt, cfg.TLSKey)
 	runtime.Assert(err)
diff --git a/code/utils/bytes.go b/code/utils/bytes.go
new file mode 100644
index 0000000..a524ae4
--- /dev/null
+++ b/code/utils/bytes.go
@@ -0,0 +1,23 @@
+package utils
+
+import "github.com/dustin/go-humanize"
+
+type Bytes uint64
+
+func (bt *Bytes) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var str string
+	err := unmarshal(&str)
+	if err != nil {
+		return err
+	}
+	n, err := humanize.ParseBytes(str)
+	if err != nil {
+		return err
+	}
+	*bt = Bytes(n)
+	return nil
+}
+
+func (bt *Bytes) Bytes() uint64 {
+	return uint64(*bt)
+}
diff --git a/go.mod b/go.mod
index 3be3662..be2e6a7 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module natpass
 go 1.16
 
 require (
+	github.com/dustin/go-humanize v1.0.0
 	github.com/lwch/daemon v0.0.0-20210628111519-5911af6cec06
 	github.com/lwch/logging v0.0.0-20210528090125-a154917d90c6
 	github.com/lwch/runtime v0.0.0-20190520054850-8c97e19e0c6d
diff --git a/go.sum b/go.sum
index fc20cf0..6db6ebd 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+github.com/dustin/go-humanize v1.0.0 h1:VSnTsYCnlFHaM2/igO1h6X3HA71jcobQuxemgkq4zYo=
+github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=