diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index a49512678..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,62 +0,0 @@
-sudo: false
-dist: trusty
-
-# With the readiness of github action, now travis CI only needs to run on master
-branches:
-  only:
-    - master
-
-language: java
-jdk:
-  - oraclejdk8
-
-before_cache:
-  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
-  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
-
-cache:
-  directories:
-    - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/
-
-before_install:
-  - gradle wrapper
-
-jobs:
-  include:
-    - stage: "WeID-Java-SDK CI"
-      script:
-        - chmod u+x .ci/script/build-ci.sh
-        - .ci/script/build-ci.sh
-        - travis_wait 40 ./gradlew check
-        - ./gradlew jacocoTestReport
-      after_success:
-        - bash <(curl -s https://codecov.io/bash)
-    - stage: "dependency pipeline"
-      script:
-        - chmod u+x .ci/script/weid-http-service/build-ci.sh
-        - .ci/script/weid-http-service/build-ci.sh
-      name: "HTTP Rest Service simple CI"
-      if: (branch = master)
-    - stage: "dependency pipeline"
-      script:
-        - chmod +x .ci/script/weid-sample/build-ci.sh
-        - .ci/script/weid-sample/build-ci.sh
-      name: "Sample simple CI"
-      if: (branch = master)
-#    - stage: "dependency pipeline"
-#      script:
-#        - chmod u+x .ci/script/weid-build-tools/build-ci.sh
-#        - .ci/script/weid-build-tools/build-ci.sh
-#      name: "Build Tools simple CI"
-#      if: (branch = master)
-
-deploy:
-  provider: releases
-  api_key: $GIT_REPO_TOKEN
-  file_glob: true
-  file: dist/app/weid-java-sdk*.jar
-  skip_cleanup: true
-  on:
-    tags: true
-    all_branches: true
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a345512d4..70b0a37a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### V1.6.4 (2020-06-16)
+- Bugfixes:
+1. Update all dependencies to mitigate potential security risks.
+
 ### V1.6.3 (2020-06-01)
 - Features:
 1. Multi-group deployment support to separate Evidence and other smart contracts.
diff --git a/VERSION b/VERSION
index f5d2a5858..6463e95e8 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.6.3
\ No newline at end of file
+1.6.4
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index 2ab79666f..106c442a3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -142,12 +142,14 @@ dependencies {
     if (gradleVer.startsWith("4")) {
         if (!gradle.startParameter.isOffline()) {
             compile logger, lombok, apache_commons, json, mysql_driver, zxing, rpc, pdfbox, protobuf, caffeine, oval
-            compile("com.webank:weid-contract-java:1.2.20") {
-                exclude group: "org.fisco-bcos", module: "web3sdk"
+            compile("com.webank:weid-contract-java:1.2.21") {
                 exclude group: "org.slf4j", module: "slf4j-log4j12"
+                // exclude group: "org.fisco-bcos", module: "web3sdk"
+                // exclude group: "org.fisco-bcos", module: "web3sdk-weevent"
             }
-            compile("org.fisco-bcos:web3sdk:2.4.1")
-            compile("org.fisco-bcos:web3sdk-weevent:1.2.6")
+            // Uncomment these two lines and exclude those above to specify web3sdk versions
+            // compile("org.fisco-bcos:web3sdk:2.4.1")
+            // compile("org.fisco-bcos:web3sdk-weevent:1.2.6")
             compile fileTree(dir: 'lib', include: '*.jar')
             testCompile logger, lombok, apache_commons, json, junit, jmockit, rpc, pdfbox, protobuf, caffeine, oval
         } else {
@@ -161,12 +163,14 @@ dependencies {
             testAnnotationProcessor 'org.projectlombok:lombok:1.18.10'
             testCompileOnly 'org.projectlombok:lombok:1.18.10'
             compile logger, apache_commons, json, mysql_driver, zxing, rpc, pdfbox, protobuf, caffeine, oval
-            compile("com.webank:weid-contract-java:1.2.20") {
-                exclude group: "org.fisco-bcos", module: "web3sdk"
+            compile("com.webank:weid-contract-java:1.2.21") {
                 exclude group: "org.slf4j", module: "slf4j-log4j12"
+                // exclude group: "org.fisco-bcos", module: "web3sdk"
+                // exclude group: "org.fisco-bcos", module: "web3sdk-weevent"
             }
-            compile("org.fisco-bcos:web3sdk:2.4.1")
-            compile("org.fisco-bcos:web3sdk-weevent:1.2.6")
+            // Uncomment these two lines and exclude those above to specify web3sdk versions
+            // compile("org.fisco-bcos:web3sdk:2.4.1")
+            // compile("org.fisco-bcos:web3sdk-weevent:1.2.6")
 			compile fileTree(dir: 'lib', include: '*.jar')
             testCompile logger, apache_commons, json, junit, jmockit, rpc, pdfbox, protobuf, caffeine, oval
         } else {