diff --git a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/NamespaceController.java b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/NamespaceController.java
index a86e09d086d8ac7ae05d0fda95a4b0da9730b739..ddab546fc25ad4bb267278931d8724f3039d10a9 100644
--- a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/NamespaceController.java
+++ b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/controller/NamespaceController.java
@@ -161,16 +161,18 @@ public class NamespaceController {
 
   @PreAuthorize(value = "@permissionValidator.hasCreateAppNamespacePermission(#appId, #appNamespace)")
   @RequestMapping(value = "/apps/{appId}/appnamespaces", method = RequestMethod.POST)
-  public AppNamespace createAppNamespace(@PathVariable String appId, @RequestBody AppNamespace appNamespace) {
+  public AppNamespace createAppNamespace(@PathVariable String appId,
+      @RequestParam(defaultValue = "true") boolean appendNamespacePrefix,
+      @RequestBody AppNamespace appNamespace) {
 
     RequestPrecondition.checkArgumentsNotEmpty(appNamespace.getAppId(), appNamespace.getName());
     if (!InputValidator.isValidAppNamespace(appNamespace.getName())) {
       throw new BadRequestException(String.format("Namespace格式错误: %s",
-              InputValidator.INVALID_CLUSTER_NAMESPACE_MESSAGE + " & "
-                      + InputValidator.INVALID_NAMESPACE_NAMESPACE_MESSAGE));
+          InputValidator.INVALID_CLUSTER_NAMESPACE_MESSAGE + " & "
+              + InputValidator.INVALID_NAMESPACE_NAMESPACE_MESSAGE));
     }
 
-    AppNamespace createdAppNamespace = appNamespaceService.createAppNamespaceInLocal(appNamespace);
+    AppNamespace createdAppNamespace = appNamespaceService.createAppNamespaceInLocal(appNamespace, appendNamespacePrefix);
 
     if (portalConfig.canAppAdminCreatePrivateNamespace() || createdAppNamespace.isPublic()) {
       assignNamespaceRoleToOperator(appId, appNamespace.getName());
diff --git a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/repository/AppNamespaceRepository.java b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/repository/AppNamespaceRepository.java
index fa7c58b959c808e4f120a309761991d1b9365577..9e3b2966ebe86901c7177621e21f1dc5a96ba532 100644
--- a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/repository/AppNamespaceRepository.java
+++ b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/repository/AppNamespaceRepository.java
@@ -12,7 +12,7 @@ public interface AppNamespaceRepository extends PagingAndSortingRepository<AppNa
 
   AppNamespace findByName(String namespaceName);
 
-  AppNamespace findByNameAndIsPublic(String namespaceName, boolean isPublic);
+  List<AppNamespace> findByNameAndIsPublic(String namespaceName, boolean isPublic);
 
   List<AppNamespace> findByIsPublicTrue();
 
diff --git a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/AppNamespaceService.java b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/AppNamespaceService.java
index d36b405279ab1c859c8df803c13f4f7c38bc58f7..b9cae5b4fd6db1d7575a0467c1105085a6b477d4 100644
--- a/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/AppNamespaceService.java
+++ b/apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/AppNamespaceService.java
@@ -9,16 +9,23 @@ import com.ctrip.framework.apollo.core.utils.StringUtils;
 import com.ctrip.framework.apollo.portal.repository.AppNamespaceRepository;
 import com.ctrip.framework.apollo.portal.spi.UserInfoHolder;
 
+import com.google.common.base.Joiner;
+import com.google.common.collect.Sets;
+import java.util.Set;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.util.List;
 import java.util.Objects;
+import org.springframework.util.CollectionUtils;
 
 @Service
 public class AppNamespaceService {
 
+  private static final int PRIVATE_APP_NAMESPACE_NOTIFICATION_COUNT = 5;
+  private static final Joiner APP_NAMESPACE_JOINER = Joiner.on(",").skipNulls();
+
   @Autowired
   private UserInfoHolder userInfoHolder;
   @Autowired
@@ -38,7 +45,17 @@ public class AppNamespaceService {
   }
 
   public AppNamespace findPublicAppNamespace(String namespaceName) {
-    return appNamespaceRepository.findByNameAndIsPublic(namespaceName, true);
+    List<AppNamespace> appNamespaces = appNamespaceRepository.findByNameAndIsPublic(namespaceName, true);
+
+    if (CollectionUtils.isEmpty(appNamespaces)) {
+      return null;
+    }
+
+    return appNamespaces.get(0);
+  }
+
+  private List<AppNamespace> findAllPrivateAppNamespaces(String namespaceName) {
+    return appNamespaceRepository.findByNameAndIsPublic(namespaceName, false);
   }
 
   public AppNamespace findByAppIdAndName(String appId, String namespaceName) {
@@ -69,8 +86,12 @@ public class AppNamespaceService {
     return Objects.isNull(appNamespaceRepository.findByAppIdAndName(appId, namespaceName));
   }
 
-  @Transactional
   public AppNamespace createAppNamespaceInLocal(AppNamespace appNamespace) {
+    return createAppNamespaceInLocal(appNamespace, true);
+  }
+
+  @Transactional
+  public AppNamespace createAppNamespaceInLocal(AppNamespace appNamespace, boolean appendNamespacePrefix) {
     String appId = appNamespace.getAppId();
 
     //add app org id as prefix
@@ -82,7 +103,7 @@ public class AppNamespaceService {
     StringBuilder appNamespaceName = new StringBuilder();
     //add prefix postfix
     appNamespaceName
-        .append(appNamespace.isPublic() ? app.getOrgId() + "." : "")
+        .append(appNamespace.isPublic() && appendNamespacePrefix ? app.getOrgId() + "." : "")
         .append(appNamespace.getName())
         .append(appNamespace.formatAsEnum() == ConfigFileFormat.Properties ? "" : "." + appNamespace.getFormat());
     appNamespace.setName(appNamespaceName.toString());
@@ -103,12 +124,9 @@ public class AppNamespaceService {
 
     appNamespace.setDataChangeLastModifiedBy(operator);
 
-    // unique check
+    // globally uniqueness check
     if (appNamespace.isPublic()) {
-      AppNamespace publicAppNamespace = findPublicAppNamespace(appNamespace.getName());
-      if (publicAppNamespace != null) {
-        throw new BadRequestException("Public AppNamespace " + appNamespace.getName() + " already exists in appId: " + publicAppNamespace.getAppId() + "!");
-      }
+      checkAppNamespaceGlobalUniqueness(appNamespace);
     }
 
     if (!appNamespace.isPublic() &&
@@ -124,6 +142,30 @@ public class AppNamespaceService {
     return createdAppNamespace;
   }
 
+  private void checkAppNamespaceGlobalUniqueness(AppNamespace appNamespace) {
+    AppNamespace publicAppNamespace = findPublicAppNamespace(appNamespace.getName());
+    if (publicAppNamespace != null) {
+      throw new BadRequestException("Public AppNamespace " + appNamespace.getName() + " already exists in appId: " + publicAppNamespace.getAppId() + "!");
+    }
+
+    List<AppNamespace> privateAppNamespaces = findAllPrivateAppNamespaces(appNamespace.getName());
+
+    if (!CollectionUtils.isEmpty(privateAppNamespaces)) {
+      Set<String> appIds = Sets.newHashSet();
+      for (AppNamespace ans : privateAppNamespaces) {
+        appIds.add(ans.getAppId());
+        if (appIds.size() == PRIVATE_APP_NAMESPACE_NOTIFICATION_COUNT) {
+          break;
+        }
+      }
+
+      throw new BadRequestException(
+          "Public AppNamespace " + appNamespace.getName() + " already exists as private AppNamespace in appId: "
+              + APP_NAMESPACE_JOINER.join(appIds) + ", etc. Please select another name!");
+    }
+  }
+
+
   @Transactional
   public AppNamespace deleteAppNamespace(String appId, String namespaceName) {
     AppNamespace appNamespace = appNamespaceRepository.findByAppIdAndName(appId, namespaceName);
diff --git a/apollo-portal/src/main/resources/static/namespace.html b/apollo-portal/src/main/resources/static/namespace.html
index 4e6c3275e89b2dff1da7e4d4644f730ba2b007f5..fbdf2ce13bf485bd588afa082cb2b39f05f182d8 100644
--- a/apollo-portal/src/main/resources/static/namespace.html
+++ b/apollo-portal/src/main/resources/static/namespace.html
@@ -95,9 +95,9 @@
                             <label class="col-sm-3 control-label">
                                 <apollorequiredfield></apollorequiredfield>
                                 名称</label>
-                            <div class="col-sm-4" valdr-form-group>
-                                <div ng-class="{'input-group':appNamespace.isPublic}">
-                                    <span class="input-group-addon" ng-show="appNamespace.isPublic"
+                            <div class="col-sm-5" valdr-form-group>
+                                <div ng-class="{'input-group':appNamespace.isPublic && appendNamespacePrefix}">
+                                    <span class="input-group-addon" ng-show="appNamespace.isPublic && appendNamespacePrefix"
                                           ng-bind="appBaseInfo.namespacePrefix"></span>
                                     <input type="text" name="namespaceName" class="form-control"
                                            ng-model="appNamespace.name">
@@ -116,9 +116,25 @@
                             </div>
 
                             &nbsp;&nbsp;
-                            <span ng-show="appNamespace.isPublic" ng-bind="concatNamespace()"
+                            <span ng-show="appNamespace.isPublic && appendNamespacePrefix" ng-bind="concatNamespace()"
                                   style="line-height: 34px;"></span>
                         </div>
+
+                        <div class="form-group" ng-show="type == 'create' && appNamespace.isPublic">
+                            <label class="col-sm-3 control-label">
+                                自动添加部门前缀
+                            </label>
+                            <div class="col-sm-6" valdr-form-group>
+                                <div>
+                                    <label class="checkbox-inline">
+                                        <input type="checkbox" ng-model="appendNamespacePrefix" />
+                                        {{appBaseInfo.namespacePrefix}}
+                                    </label>
+                                </div>
+                                <small>(公共Namespace的名称需要全局唯一，添加部门前缀有助于保证全局唯一性)</small>
+                            </div>
+                        </div>
+
                         <div class="form-group" ng-show="type == 'create' && (pageSetting.canAppAdminCreatePrivateNamespace || hasRootPermission)">
                             <label class="col-sm-3 control-label">
                                 <apollorequiredfield></apollorequiredfield>
diff --git a/apollo-portal/src/main/resources/static/scripts/controller/NamespaceController.js b/apollo-portal/src/main/resources/static/scripts/controller/NamespaceController.js
index 92397508a19a933484d44771ec5ffd5f90204288..cd82a89d2a0ea2086a1ff1b3b5f2f3567464acc2 100644
--- a/apollo-portal/src/main/resources/static/scripts/controller/NamespaceController.js
+++ b/apollo-portal/src/main/resources/static/scripts/controller/NamespaceController.js
@@ -11,6 +11,7 @@ namespace_module.controller("LinkNamespaceController",
                                  $scope.step = 1;
 
                                  $scope.submitBtnDisabled = false;
+                                 $scope.appendNamespacePrefix = true;
 
                                  PermissionService.has_root_permission().then(function (result) {
                                      $scope.hasRootPermission = result.hasPermission;
@@ -125,7 +126,9 @@ namespace_module.controller("LinkNamespaceController",
                                          }
 
                                          $scope.submitBtnDisabled = true;
-                                         NamespaceService.createAppNamespace($scope.appId, $scope.appNamespace).then(
+                                         //only append namespace prefix for public app namespace
+                                         var appendNamespacePrefix = $scope.appNamespace.isPublic ? $scope.appendNamespacePrefix : false;
+                                         NamespaceService.createAppNamespace($scope.appId, $scope.appNamespace, appendNamespacePrefix).then(
                                              function (result) {
                                                  $scope.step = 2;
                                                  setTimeout(function () {
diff --git a/apollo-portal/src/main/resources/static/scripts/services/NamespaceService.js b/apollo-portal/src/main/resources/static/scripts/services/NamespaceService.js
index d7b429bccfa56c58f3e15cc8dfaa72100346ede4..8d79dc6c46c6be2c05281f318bd94fca26259d50 100644
--- a/apollo-portal/src/main/resources/static/scripts/services/NamespaceService.js
+++ b/apollo-portal/src/main/resources/static/scripts/services/NamespaceService.js
@@ -12,7 +12,7 @@ appService.service("NamespaceService", ['$resource', '$q', function ($resource,
         },
         createAppNamespace: {
             method: 'POST',
-            url: '/apps/:appId/appnamespaces',
+            url: '/apps/:appId/appnamespaces?appendNamespacePrefix=:appendNamespacePrefix',
             isArray: false
         },
         getNamespacePublishInfo: {
@@ -60,11 +60,12 @@ appService.service("NamespaceService", ['$resource', '$q', function ($resource,
         return d.promise;
     }
 
-    function createAppNamespace(appId, appnamespace) {
+    function createAppNamespace(appId, appnamespace, appendNamespacePrefix) {
         var d = $q.defer();
         namespace_source.createAppNamespace({
-                                                appId: appId
-                                            }, appnamespace, function (result) {
+            appId: appId,
+            appendNamespacePrefix: appendNamespacePrefix
+          }, appnamespace, function (result) {
             d.resolve(result);
         }, function (result) {
             d.reject(result);
diff --git a/apollo-portal/src/test/java/com/ctrip/framework/apollo/portal/service/AppNamespaceServiceTest.java b/apollo-portal/src/test/java/com/ctrip/framework/apollo/portal/service/AppNamespaceServiceTest.java
index 4ee286946c92acf2b1a7f19b65e1dae2f90d64d2..980f0a441d43f92f720c6b4fbdd05b6edd4280eb 100644
--- a/apollo-portal/src/test/java/com/ctrip/framework/apollo/portal/service/AppNamespaceServiceTest.java
+++ b/apollo-portal/src/test/java/com/ctrip/framework/apollo/portal/service/AppNamespaceServiceTest.java
@@ -76,6 +76,31 @@ public class AppNamespaceServiceTest extends AbstractIntegrationTest {
     appNamespaceService.createAppNamespaceInLocal(appNamespace);
   }
 
+  @Test
+  @Sql(scripts = "/sql/appnamespaceservice/init-appnamespace.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/sql/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)
+  public void testCreatePublicAppNamespaceNotExistedWithNoAppendnamespacePrefix() {
+    AppNamespace appNamespace = assmbleBaseAppNamespace();
+    appNamespace.setPublic(true);
+    appNamespace.setName("old");
+
+    AppNamespace createdAppNamespace = appNamespaceService.createAppNamespaceInLocal(appNamespace, false);
+
+    Assert.assertNotNull(createdAppNamespace);
+    Assert.assertEquals(appNamespace.getName(), createdAppNamespace.getName());
+  }
+
+  @Test(expected = BadRequestException.class)
+  @Sql(scripts = "/sql/appnamespaceservice/init-appnamespace.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/sql/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)
+  public void testCreatePublicAppNamespaceExistedWithNoAppendnamespacePrefix() {
+    AppNamespace appNamespace = assmbleBaseAppNamespace();
+    appNamespace.setPublic(true);
+    appNamespace.setName("datasource");
+
+    appNamespaceService.createAppNamespaceInLocal(appNamespace, false);
+  }
+
   @Test
   @Sql(scripts = "/sql/appnamespaceservice/init-appnamespace.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
   @Sql(scripts = "/sql/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)