diff --git a/pkg/server/io/helpers.go b/pkg/server/io/helpers.go
index 88b5c076d..d41a67726 100644
--- a/pkg/server/io/helpers.go
+++ b/pkg/server/io/helpers.go
@@ -27,6 +27,7 @@ import (
 	"github.com/containerd/containerd"
 	"github.com/containerd/fifo"
 	"golang.org/x/net/context"
+	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 )
 
 // AttachOptions specifies how to attach to a container.
@@ -47,9 +48,9 @@ const (
 	// Stdin stream type.
 	Stdin StreamType = "stdin"
 	// Stdout stream type.
-	Stdout StreamType = "stdout"
+	Stdout StreamType = StreamType(runtime.Stdout)
 	// Stderr stream type.
-	Stderr StreamType = "stderr"
+	Stderr StreamType = StreamType(runtime.Stderr)
 )
 
 type wgCloser struct {
diff --git a/pkg/server/io/logger.go b/pkg/server/io/logger.go
index da2c4fc0e..11f85a625 100644
--- a/pkg/server/io/logger.go
+++ b/pkg/server/io/logger.go
@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/golang/glog"
+	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 
 	cioutil "github.com/kubernetes-incubator/cri-containerd/pkg/ioutil"
 )
@@ -41,7 +42,7 @@ const (
 	// POSIX.1 says that write less than PIPE_BUF is atmoic.
 	pipeBufSize = 4096
 	// bufSize is the size of the read buffer.
-	bufSize = pipeBufSize - len(timestampFormat) - len(Stdout) - 2 /*2 delimiter*/ - 1 /*eol*/
+	bufSize = pipeBufSize - len(timestampFormat) - len(Stdout) - len(runtime.LogTagPartial) - 3 /*3 delimiter*/ - 1 /*eol*/
 )
 
 // NewDiscardLogger creates logger which discards all the input.
@@ -67,10 +68,11 @@ func redirectLogs(path string, rc io.ReadCloser, wc io.WriteCloser, stream Strea
 	defer wc.Close()
 	streamBytes := []byte(stream)
 	delimiterBytes := []byte{delimiter}
+	partialBytes := []byte(runtime.LogTagPartial)
+	fullBytes := []byte(runtime.LogTagFull)
 	r := bufio.NewReaderSize(rc, bufSize)
 	for {
-		// TODO(random-liu): Better define CRI log format, and escape newline in log.
-		lineBytes, _, err := r.ReadLine()
+		lineBytes, isPrefix, err := r.ReadLine()
 		if err == io.EOF {
 			glog.V(4).Infof("Finish redirecting log file %q", path)
 			return
@@ -79,8 +81,12 @@ func redirectLogs(path string, rc io.ReadCloser, wc io.WriteCloser, stream Strea
 			glog.Errorf("An error occurred when redirecting log file %q: %v", path, err)
 			return
 		}
+		tagBytes := fullBytes
+		if isPrefix {
+			tagBytes = partialBytes
+		}
 		timestampBytes := time.Now().AppendFormat(nil, time.RFC3339Nano)
-		data := bytes.Join([][]byte{timestampBytes, streamBytes, lineBytes}, delimiterBytes)
+		data := bytes.Join([][]byte{timestampBytes, streamBytes, tagBytes, lineBytes}, delimiterBytes)
 		data = append(data, eol)
 		if _, err := wc.Write(data); err != nil {
 			glog.Errorf("Fail to write %q log to log file %q: %v", stream, path, err)
diff --git a/pkg/server/io/logger_test.go b/pkg/server/io/logger_test.go
index 9b788c8b2..1dbc03916 100644
--- a/pkg/server/io/logger_test.go
+++ b/pkg/server/io/logger_test.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 
 	cioutil "github.com/kubernetes-incubator/cri-containerd/pkg/ioutil"
 )
@@ -33,11 +34,16 @@ func TestRedirectLogs(t *testing.T) {
 	for desc, test := range map[string]struct {
 		input   string
 		stream  StreamType
+		tag     []runtime.LogTag
 		content []string
 	}{
 		"stdout log": {
 			input:  "test stdout log 1\ntest stdout log 2",
 			stream: Stdout,
+			tag: []runtime.LogTag{
+				runtime.LogTagFull,
+				runtime.LogTagFull,
+			},
 			content: []string{
 				"test stdout log 1",
 				"test stdout log 2",
@@ -46,15 +52,25 @@ func TestRedirectLogs(t *testing.T) {
 		"stderr log": {
 			input:  "test stderr log 1\ntest stderr log 2",
 			stream: Stderr,
+			tag: []runtime.LogTag{
+				runtime.LogTagFull,
+				runtime.LogTagFull,
+			},
 			content: []string{
 				"test stderr log 1",
 				"test stderr log 2",
 			},
 		},
 		"long log": {
-			input:  strings.Repeat("a", bufSize+10) + "\n",
+			input:  strings.Repeat("a", 2*bufSize+10) + "\n",
 			stream: Stdout,
+			tag: []runtime.LogTag{
+				runtime.LogTagPartial,
+				runtime.LogTagPartial,
+				runtime.LogTagFull,
+			},
 			content: []string{
+				strings.Repeat("a", bufSize),
 				strings.Repeat("a", bufSize),
 				strings.Repeat("a", 10),
 			},
@@ -70,12 +86,13 @@ func TestRedirectLogs(t *testing.T) {
 		lines = lines[:len(lines)-1] // Discard empty string after last \n
 		assert.Len(t, lines, len(test.content))
 		for i := range lines {
-			fields := strings.SplitN(lines[i], string([]byte{delimiter}), 3)
-			require.Len(t, fields, 3)
+			fields := strings.SplitN(lines[i], string([]byte{delimiter}), 4)
+			require.Len(t, fields, 4)
 			_, err := time.Parse(timestampFormat, fields[0])
 			assert.NoError(t, err)
 			assert.EqualValues(t, test.stream, fields[1])
-			assert.Equal(t, test.content[i], fields[2])
+			assert.Equal(t, string(test.tag[i]), fields[2])
+			assert.Equal(t, test.content[i], fields[3])
 		}
 	}
 }