diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97273c48d..e3c4e2a33 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -116,7 +116,7 @@
 * [#175] Support deregistering instance automatically.
 * [#176] Naming client query instance method should bypass local cache at client start.
 * [#177] Console supports registering new empty service and delete empty service.
-* [#181] NPE when adding a instance if no leader in the raft cluster.
+* [#181] NPE when adding an instance if no leader in the raft cluster.
 * [#193] Configure host domain name cause nacos server cluster is unavailable.
 * [#209] Disable service and cluster level customization in client registerInstance method.
 * [#214] Please support Java 11.
diff --git a/address/src/main/java/com/alibaba/nacos/address/component/AddressServerGeneratorManager.java b/address/src/main/java/com/alibaba/nacos/address/component/AddressServerGeneratorManager.java
index dc2a5a52a..e0a1b8113 100644
--- a/address/src/main/java/com/alibaba/nacos/address/component/AddressServerGeneratorManager.java
+++ b/address/src/main/java/com/alibaba/nacos/address/component/AddressServerGeneratorManager.java
@@ -96,7 +96,7 @@ public class AddressServerGeneratorManager {
     /**
      * Generate response ips.
      *
-     * @param instanceList a instance set will generate string response to client.
+     * @param instanceList an instance set will generate string response to client.
      * @return the result of response to client
      */
     public String generateResponseIps(List<com.alibaba.nacos.api.naming.pojo.Instance> instanceList) {
@@ -113,7 +113,7 @@ public class AddressServerGeneratorManager {
     /**
      * Generate nacos service name.
      *
-     * @param rawServiceName the raw service name will not contains the {@link Constants#DEFAULT_GROUP}.
+     * @param rawServiceName the raw service name will not contain the {@link Constants#DEFAULT_GROUP}.
      * @return the nacos service name
      */
     public String generateNacosServiceName(String rawServiceName) {
diff --git a/api/src/main/java/com/alibaba/nacos/api/naming/NamingService.java b/api/src/main/java/com/alibaba/nacos/api/naming/NamingService.java
index d27ad5bd0..e0cbb83d3 100644
--- a/api/src/main/java/com/alibaba/nacos/api/naming/NamingService.java
+++ b/api/src/main/java/com/alibaba/nacos/api/naming/NamingService.java
@@ -33,7 +33,7 @@ import java.util.List;
 public interface NamingService {
     
     /**
-     * register a instance to service.
+     * register an instance to service.
      *
      * @param serviceName name of service
      * @param ip          instance ip
@@ -43,7 +43,7 @@ public interface NamingService {
     void registerInstance(String serviceName, String ip, int port) throws NacosException;
     
     /**
-     * register a instance to service.
+     * register an instance to service.
      *
      * @param serviceName name of service
      * @param groupName   group of service
@@ -54,7 +54,7 @@ public interface NamingService {
     void registerInstance(String serviceName, String groupName, String ip, int port) throws NacosException;
     
     /**
-     * register a instance to service with specified cluster name.
+     * register an instance to service with specified cluster name.
      *
      * @param serviceName name of service
      * @param ip          instance ip
@@ -65,7 +65,7 @@ public interface NamingService {
     void registerInstance(String serviceName, String ip, int port, String clusterName) throws NacosException;
     
     /**
-     * register a instance to service with specified cluster name.
+     * register an instance to service with specified cluster name.
      *
      * @param serviceName name of service
      * @param groupName   group of service
@@ -78,7 +78,7 @@ public interface NamingService {
             throws NacosException;
     
     /**
-     * register a instance to service with specified instance properties.
+     * register an instance to service with specified instance properties.
      *
      * @param serviceName name of service
      * @param instance    instance to register
@@ -87,7 +87,7 @@ public interface NamingService {
     void registerInstance(String serviceName, Instance instance) throws NacosException;
     
     /**
-     * register a instance to service with specified instance properties.
+     * register an instance to service with specified instance properties.
      *
      * @param serviceName name of service
      * @param groupName   group of service
diff --git a/api/src/main/java/com/alibaba/nacos/api/naming/pojo/healthcheck/HealthCheckerFactory.java b/api/src/main/java/com/alibaba/nacos/api/naming/pojo/healthcheck/HealthCheckerFactory.java
index 3adc0b34f..e8236e7c9 100644
--- a/api/src/main/java/com/alibaba/nacos/api/naming/pojo/healthcheck/HealthCheckerFactory.java
+++ b/api/src/main/java/com/alibaba/nacos/api/naming/pojo/healthcheck/HealthCheckerFactory.java
@@ -69,7 +69,7 @@ public class HealthCheckerFactory {
     }
     
     /**
-     * Deserialize and create a instance of health checker.
+     * Deserialize and create an instance of health checker.
      *
      * @param jsonString json string of health checker
      * @return new instance
@@ -83,7 +83,7 @@ public class HealthCheckerFactory {
     }
     
     /**
-     * Serialize a instance of health checker to json.
+     * Serialize an instance of health checker to json.
      *
      * @param healthChecker health checker instance
      * @return son string after serializing
diff --git a/client/src/main/java/com/alibaba/nacos/client/naming/remote/NamingClientProxy.java b/client/src/main/java/com/alibaba/nacos/client/naming/remote/NamingClientProxy.java
index 5792ffef6..6fc40c35c 100644
--- a/client/src/main/java/com/alibaba/nacos/client/naming/remote/NamingClientProxy.java
+++ b/client/src/main/java/com/alibaba/nacos/client/naming/remote/NamingClientProxy.java
@@ -34,7 +34,7 @@ import java.util.List;
 public interface NamingClientProxy extends Closeable {
     
     /**
-     * Register a instance to service with specified instance properties.
+     * Register an instance to service with specified instance properties.
      *
      * @param serviceName name of service
      * @param groupName   group of service