diff --git a/README.md b/README.md
index 5bbbfcdf..c0bd1e17 100644
--- a/README.md
+++ b/README.md
@@ -203,7 +203,7 @@ Step 1-3 are to be done on the host OS (Linux):
 
 3. Run the Occlum Docker container, which has Occlum and its demos preinstalled:
     ```
-    docker run -it --device /dev/isgx occlum/occlum:0.20.0-ubuntu18.04
+    docker run -it --device /dev/isgx occlum/occlum:[version]-ubuntu18.04
     ```
 
 Step 4-5 are to be done on the guest OS running inside the Docker container:
diff --git a/src/exec/Cargo.lock b/src/exec/Cargo.lock
index 26b3a68c..3078e6cb 100644
--- a/src/exec/Cargo.lock
+++ b/src/exec/Cargo.lock
@@ -419,7 +419,7 @@ dependencies = [
 
 [[package]]
 name = "occlum_exec"
-version = "0.20.0"
+version = "0.21.0"
 dependencies = [
  "chrono 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/src/exec/Cargo.toml b/src/exec/Cargo.toml
index 41e03ee7..e919f57a 100644
--- a/src/exec/Cargo.toml
+++ b/src/exec/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "occlum_exec"
-version = "0.20.0"
+version = "0.21.0"
 edition = "2018"
 
 [lib]
diff --git a/src/libos/Cargo.lock b/src/libos/Cargo.lock
index 5a51ced8..93583433 100644
--- a/src/libos/Cargo.lock
+++ b/src/libos/Cargo.lock
@@ -2,7 +2,7 @@
 # It is not intended for manual editing.
 [[package]]
 name = "Occlum"
-version = "0.20.0"
+version = "0.21.0"
 dependencies = [
  "aligned",
  "atomic",
diff --git a/src/libos/Cargo.toml b/src/libos/Cargo.toml
index c6aa2ec7..11ecc5dd 100644
--- a/src/libos/Cargo.toml
+++ b/src/libos/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "Occlum"
-version = "0.20.0"
+version = "0.21.0"
 edition = "2018"
 
 [lib]
diff --git a/src/pal/include/occlum_version.h b/src/pal/include/occlum_version.h
index 97aa6e59..5d65748f 100644
--- a/src/pal/include/occlum_version.h
+++ b/src/pal/include/occlum_version.h
@@ -1,9 +1,9 @@
 #ifndef _OCCLUM_VERSION_H_
 #define _OCCLUM_VERSION_H_
 
-// Version = 0.20.0
+// Version = 0.21.0
 #define OCCLUM_MAJOR_VERSION    0
-#define OCCLUM_MINOR_VERSION    20
+#define OCCLUM_MINOR_VERSION    21
 #define OCCLUM_PATCH_VERSION    0
 
 #define STRINGIZE_PRE(X) #X
diff --git a/tools/update_version.sh b/tools/update_version.sh
new file mode 100755
index 00000000..ec28c95d
--- /dev/null
+++ b/tools/update_version.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+
+if [ $# != 4 ] ; then
+echo "USAGE: $0 major_version minor_version patch_version path"
+echo " e.g.: $0 1 2 3 ."
+exit 1;
+fi
+
+OCCLUM_MAJOR_VERSION=$1
+OCCLUM_MINOR_VERSION=$2
+OCCLUM_PATCH_VERSION=$3
+
+dir=$4
+if [ ! -d $dir ];then
+echo $dir is not dir
+fi
+
+echo "update version to $OCCLUM_MAJOR_VERSION.$OCCLUM_MINOR_VERSION.$OCCLUM_PATCH_VERSION"
+
+cd $dir
+cd src/libos/
+sed -i '/^version =/c\version = "'$OCCLUM_MAJOR_VERSION'.'$OCCLUM_MINOR_VERSION'.'$OCCLUM_PATCH_VERSION'"' Cargo.toml
+sed -i '/^name = "Occlum"/{n;d}' Cargo.lock
+sed -i '/^name = "Occlum"/a\version = "'$OCCLUM_MAJOR_VERSION'.'$OCCLUM_MINOR_VERSION'.'$OCCLUM_PATCH_VERSION'"' Cargo.lock
+cd ../../
+
+cd src/exec/
+sed -i '/^version =/c\version = "'$OCCLUM_MAJOR_VERSION'.'$OCCLUM_MINOR_VERSION'.'$OCCLUM_PATCH_VERSION'"' Cargo.toml
+sed -i '/^name = "occlum_exec"/{n;d}' Cargo.lock
+sed -i '/^name = "occlum_exec"/a\version = "'$OCCLUM_MAJOR_VERSION'.'$OCCLUM_MINOR_VERSION'.'$OCCLUM_PATCH_VERSION'"' Cargo.lock
+cd ../../
+
+cd src/pal/include/
+cat>occlum_version.h<<EOF
+// This file generated by update_version.sh
+// Do not update this file manually.
+#ifndef _OCCLUM_VERSION_H_
+#define _OCCLUM_VERSION_H_
+
+// Version = $OCCLUM_MAJOR_VERSION.$OCCLUM_MINOR_VERSION.$OCCLUM_PATCH_VERSION
+#define OCCLUM_MAJOR_VERSION    $OCCLUM_MAJOR_VERSION
+#define OCCLUM_MINOR_VERSION    $OCCLUM_MINOR_VERSION
+#define OCCLUM_PATCH_VERSION    $OCCLUM_PATCH_VERSION
+
+#define STRINGIZE_PRE(X) #X
+#define STRINGIZE(X) STRINGIZE_PRE(X)
+
+#define OCCLUM_VERSION_NUM_STR STRINGIZE(OCCLUM_MAJOR_VERSION) "." \\
+                    STRINGIZE(OCCLUM_MAJOR_VERSION) "." STRINGIZE(OCCLUM_PATCH_VERSION)
+
+#endif
+EOF