diff --git a/apollo-mockserver/src/main/java/com/ctrip/framework/apollo/mockserver/EmbeddedApollo.java b/apollo-mockserver/src/main/java/com/ctrip/framework/apollo/mockserver/EmbeddedApollo.java
index 7696b5363e296f98216e060cc69138d2cf190ab4..1efb8a6f073a4e4a7276ed568829fd81358aa87c 100644
--- a/apollo-mockserver/src/main/java/com/ctrip/framework/apollo/mockserver/EmbeddedApollo.java
+++ b/apollo-mockserver/src/main/java/com/ctrip/framework/apollo/mockserver/EmbeddedApollo.java
@@ -5,14 +5,13 @@ import com.ctrip.framework.apollo.core.dto.ApolloConfig;
 import com.ctrip.framework.apollo.core.dto.ApolloConfigNotification;
 import com.ctrip.framework.apollo.core.utils.ResourceUtils;
 import com.ctrip.framework.apollo.internals.ConfigServiceLocator;
-import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
 import java.lang.reflect.Method;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -38,8 +37,8 @@ public class EmbeddedApollo extends ExternalResource {
   private static ConfigServiceLocator CONFIG_SERVICE_LOCATOR;
 
   private final Gson gson = new Gson();
-  private final Map<String, Map<String, String>> addedOrModifiedPropertiesOfNamespace = new HashMap<>();
-  private final Map<String, Set<String>> deletedKeysOfNamespace = new HashMap<>();
+  private final Map<String, Map<String, String>> addedOrModifiedPropertiesOfNamespace = Maps.newConcurrentMap();
+  private final Map<String, Set<String>> deletedKeysOfNamespace = Maps.newConcurrentMap();
 
   private MockWebServer server;
 
@@ -151,7 +150,7 @@ public class EmbeddedApollo extends ExternalResource {
     if (addedOrModifiedPropertiesOfNamespace.containsKey(namespace)) {
       addedOrModifiedPropertiesOfNamespace.get(namespace).put(someKey, someValue);
     } else {
-      Map<String, String> m = new HashMap<>();
+      Map<String, String> m = Maps.newConcurrentMap();
       m.put(someKey, someValue);
       addedOrModifiedPropertiesOfNamespace.put(namespace, m);
     }
@@ -164,7 +163,9 @@ public class EmbeddedApollo extends ExternalResource {
     if (deletedKeysOfNamespace.containsKey(namespace)) {
       deletedKeysOfNamespace.get(namespace).add(someKey);
     } else {
-      deletedKeysOfNamespace.put(namespace, ImmutableSet.of(someKey));
+      Set<String> m = Sets.newConcurrentHashSet();
+      m.add(someKey);
+      deletedKeysOfNamespace.put(namespace, m);
     }
   }
 
diff --git a/apollo-mockserver/src/test/java/com/ctrip/framework/apollo/mockserver/ApolloMockServerApiTest.java b/apollo-mockserver/src/test/java/com/ctrip/framework/apollo/mockserver/ApolloMockServerApiTest.java
index 8c0ffdcd54b4b0c38a501ea97dc31f2e4e3a2999..dc930f3e257b13acf93c6d72d1f97369f1ca063b 100644
--- a/apollo-mockserver/src/test/java/com/ctrip/framework/apollo/mockserver/ApolloMockServerApiTest.java
+++ b/apollo-mockserver/src/test/java/com/ctrip/framework/apollo/mockserver/ApolloMockServerApiTest.java
@@ -1,6 +1,7 @@
 package com.ctrip.framework.apollo.mockserver;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import com.ctrip.framework.apollo.Config;
@@ -8,7 +9,10 @@ import com.ctrip.framework.apollo.ConfigChangeListener;
 import com.ctrip.framework.apollo.ConfigService;
 import com.ctrip.framework.apollo.model.ConfigChangeEvent;
 import com.google.common.util.concurrent.SettableFuture;
+
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
+
 import org.junit.ClassRule;
 import org.junit.Test;
 
@@ -51,7 +55,79 @@ public class ApolloMockServerApiTest {
 
     assertEquals(someNewValue, otherConfig.getProperty("key1", null));
     assertEquals("otherValue2", otherConfig.getProperty("key2", null));
-
     assertTrue(changeEvent.isChanged("key1"));
   }
+
+  @Test
+  public void testUpdateSamePropertyTwice() throws Exception {
+    String someNewValue = "someNewValue";
+
+    Config otherConfig = ConfigService.getConfig(anotherNamespace);
+
+    final Semaphore changes = new Semaphore(0);
+
+    otherConfig.addChangeListener(new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        changes.release();
+      }
+    });
+
+    assertEquals("otherValue3", otherConfig.getProperty("key3", null));
+
+    embeddedApollo.addOrModifyProperty(anotherNamespace, "key3", someNewValue);
+    embeddedApollo.addOrModifyProperty(anotherNamespace, "key3", someNewValue);
+
+    assertTrue(changes.tryAcquire(5, TimeUnit.SECONDS));
+    assertEquals(someNewValue, otherConfig.getProperty("key3", null));
+    assertEquals(0, changes.availablePermits());
+  }
+
+  @Test
+  public void testDeleteProperties() throws Exception {
+    Config otherConfig = ConfigService.getConfig(anotherNamespace);
+
+    final SettableFuture<ConfigChangeEvent> future = SettableFuture.create();
+
+    otherConfig.addChangeListener(new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        future.set(changeEvent);
+      }
+    });
+
+    assertEquals("otherValue4", otherConfig.getProperty("key4", null));
+    assertEquals("otherValue5", otherConfig.getProperty("key5", null));
+
+    embeddedApollo.deleteProperty(anotherNamespace, "key4");
+
+    ConfigChangeEvent changeEvent = future.get(5, TimeUnit.SECONDS);
+
+    assertNull(otherConfig.getProperty("key4", null));
+    assertEquals("otherValue5", otherConfig.getProperty("key5", null));
+    assertTrue(changeEvent.isChanged("key4"));
+  }
+
+  @Test
+  public void testDeleteSamePropertyTwice() throws Exception {
+    Config otherConfig = ConfigService.getConfig(anotherNamespace);
+
+    final Semaphore changes = new Semaphore(0);
+
+    otherConfig.addChangeListener(new ConfigChangeListener() {
+      @Override
+      public void onChange(ConfigChangeEvent changeEvent) {
+        changes.release();
+      }
+    });
+
+    assertEquals("otherValue6", otherConfig.getProperty("key6", null));
+
+    embeddedApollo.deleteProperty(anotherNamespace, "key6");
+    embeddedApollo.deleteProperty(anotherNamespace, "key6");
+
+    assertTrue(changes.tryAcquire(5, TimeUnit.SECONDS));
+    assertNull(otherConfig.getProperty("key6", null));
+    assertEquals(0, changes.availablePermits());
+  }
 }
diff --git a/apollo-mockserver/src/test/resources/mockdata-anotherNamespace.properties b/apollo-mockserver/src/test/resources/mockdata-anotherNamespace.properties
index 9f6e4ac5dc1d1f3507de220f1ffaa512cc780eca..e3c5790d1b52fba76f217c4ccccab3824140811f 100644
--- a/apollo-mockserver/src/test/resources/mockdata-anotherNamespace.properties
+++ b/apollo-mockserver/src/test/resources/mockdata-anotherNamespace.properties
@@ -1,2 +1,6 @@
 key1=otherValue1
 key2=otherValue2
+key3=otherValue3
+key4=otherValue4
+key5=otherValue5
+key6=otherValue6