diff --git a/rpc/compiler/go_generator.cc b/rpc/compiler/go_generator.cc
index 21484f3b..bbc5a562 100644
--- a/rpc/compiler/go_generator.cc
+++ b/rpc/compiler/go_generator.cc
@@ -42,6 +42,7 @@
 
 using namespace std;
 
+// TODO(zhaoq): Support go_package option.
 namespace grpc_go_generator {
 
 bool NoStreaming(const google::protobuf::MethodDescriptor* method) {
@@ -88,25 +89,42 @@ std::string BadToUnderscore(std::string str) {
   return str;
 }
 
-const string GetFullName(const string& selfPkg,
-                         const string& msgPkg,
-                         const string& msgName) {
-  if (selfPkg == msgPkg) {
-    return msgName;
+string GenerateFullGoPackage(const google::protobuf::FileDescriptor* file) {
+  // In opensouce environment, assume each directory has at most one package.
+  size_t pos = file->name().find_last_of('/');
+  if (pos != string::npos) {
+    return file->name().substr(0, pos);
   }
-  return BadToUnderscore(msgPkg) + "." + msgName;
+  return "";
+}
+
+const string GetFullMessageQualifiedName(
+    const google::protobuf::Descriptor* desc,
+    set<string>& imports,
+    map<string, string>& import_alias) {
+  string pkg = GenerateFullGoPackage(desc->file());
+  if (imports.find(pkg) == imports.end()) {
+    // The message is in the same package as the services definition.
+    return desc->name();
+  }
+  if (import_alias.find(pkg) != import_alias.end()) {
+    // The message is in a package whose name is as same as the one consisting
+    // of the service definition. Use the alias to differentiate.
+    return import_alias[pkg] + "." + desc->name();
+  }
+  return BadToUnderscore(desc->file()->package()) + "." + desc->name();
 }
 
 void PrintClientMethodDef(google::protobuf::io::Printer* printer,
                           const google::protobuf::MethodDescriptor* method,
-                          map<string, string>* vars) {
+                          map<string, string>* vars,
+                          set<string>& imports,
+                          map<string, string>& import_alias) {
   (*vars)["Method"] = method->name();
-  (*vars)["Request"] = GetFullName((*vars)["PackageName"],
-                                   method->input_type()->file()->package(),
-                                   method->input_type()->name());
-  (*vars)["Response"] = GetFullName((*vars)["PackageName"],
-                                   method->output_type()->file()->package(),
-                                   method->output_type()->name());
+  (*vars)["Request"] =
+      GetFullMessageQualifiedName(method->input_type(), imports, import_alias);
+  (*vars)["Response"] =
+      GetFullMessageQualifiedName(method->output_type(), imports, import_alias);
   if (NoStreaming(method)) {
     printer->Print(*vars,
                    "\t$Method$(ctx context.Context, in *$Request$, opts "
@@ -130,14 +148,14 @@ void PrintClientMethodDef(google::protobuf::io::Printer* printer,
 
 void PrintClientMethodImpl(google::protobuf::io::Printer* printer,
                            const google::protobuf::MethodDescriptor* method,
-                           map<string, string>* vars) {
+                           map<string, string>* vars,
+                           set<string>& imports,
+                           map<string, string>& import_alias) {
   (*vars)["Method"] = method->name();
-  (*vars)["Request"] = GetFullName((*vars)["PackageName"],
-                                   method->input_type()->file()->package(),
-                                   method->input_type()->name());
-  (*vars)["Response"] = GetFullName((*vars)["PackageName"],
-                                   method->output_type()->file()->package(),
-                                   method->output_type()->name());
+  (*vars)["Request"] =
+      GetFullMessageQualifiedName(method->input_type(), imports, import_alias);
+  (*vars)["Response"] =
+      GetFullMessageQualifiedName(method->output_type(), imports, import_alias);
   if (NoStreaming(method)) {
     printer->Print(
         *vars,
@@ -279,12 +297,14 @@ void PrintClientMethodImpl(google::protobuf::io::Printer* printer,
 
 void PrintClient(google::protobuf::io::Printer* printer,
                  const google::protobuf::ServiceDescriptor* service,
-                 map<string, string>* vars) {
+                 map<string, string>* vars,
+                 set<string>& imports,
+                 map<string, string>& import_alias) {
   (*vars)["Service"] = service->name();
   (*vars)["ServiceStruct"] = LowerCaseService(service->name());
   printer->Print(*vars, "type $Service$Client interface {\n");
   for (int i = 0; i < service->method_count(); ++i) {
-    PrintClientMethodDef(printer, service->method(i), vars);
+    PrintClientMethodDef(printer, service->method(i), vars, imports, import_alias);
   }
   printer->Print("}\n\n");
 
@@ -298,20 +318,20 @@ void PrintClient(google::protobuf::io::Printer* printer,
       "\treturn &$ServiceStruct$Client{cc}\n"
       "}\n\n");
   for (int i = 0; i < service->method_count(); ++i) {
-    PrintClientMethodImpl(printer, service->method(i), vars);
+    PrintClientMethodImpl(printer, service->method(i), vars, imports, import_alias);
   }
 }
 
 void PrintServerMethodDef(google::protobuf::io::Printer* printer,
                           const google::protobuf::MethodDescriptor* method,
-                          map<string, string>* vars) {
+                          map<string, string>* vars,
+                          set<string>& imports,
+                          map<string, string>& import_alias) {
   (*vars)["Method"] = method->name();
-  (*vars)["Request"] = GetFullName((*vars)["PackageName"],
-                                   method->input_type()->file()->package(),
-                                   method->input_type()->name());
-  (*vars)["Response"] = GetFullName((*vars)["PackageName"],
-                                   method->output_type()->file()->package(),
-                                   method->output_type()->name());
+  (*vars)["Request"] =
+      GetFullMessageQualifiedName(method->input_type(), imports, import_alias);
+  (*vars)["Response"] =
+      GetFullMessageQualifiedName(method->output_type(), imports, import_alias);
   if (NoStreaming(method)) {
     printer->Print(
         *vars,
@@ -328,14 +348,14 @@ void PrintServerMethodDef(google::protobuf::io::Printer* printer,
 
 void PrintServerHandler(google::protobuf::io::Printer* printer,
                         const google::protobuf::MethodDescriptor* method,
-                        map<string, string>* vars) {
+                        map<string, string>* vars,
+                        set<string>& imports,
+                        map<string, string>& import_alias) {
   (*vars)["Method"] = method->name();
-  (*vars)["Request"] = GetFullName((*vars)["PackageName"],
-                                   method->input_type()->file()->package(),
-                                   method->input_type()->name());
-  (*vars)["Response"] = GetFullName((*vars)["PackageName"],
-                                   method->output_type()->file()->package(),
-                                   method->output_type()->name());
+  (*vars)["Request"] =
+      GetFullMessageQualifiedName(method->input_type(), imports, import_alias);
+  (*vars)["Response"] =
+      GetFullMessageQualifiedName(method->output_type(), imports, import_alias);
   if (NoStreaming(method)) {
     printer->Print(
         *vars,
@@ -473,11 +493,13 @@ void PrintServerStreamingMethodDesc(
 
 void PrintServer(google::protobuf::io::Printer* printer,
                  const google::protobuf::ServiceDescriptor* service,
-                 map<string, string>* vars) {
+                 map<string, string>* vars,
+                 set<string>& imports,
+                 map<string, string>& import_alias) {
   (*vars)["Service"] = service->name();
   printer->Print(*vars, "type $Service$Server interface {\n");
   for (int i = 0; i < service->method_count(); ++i) {
-    PrintServerMethodDef(printer, service->method(i), vars);
+    PrintServerMethodDef(printer, service->method(i), vars, imports, import_alias);
   }
   printer->Print("}\n\n");
 
@@ -487,7 +509,7 @@ void PrintServer(google::protobuf::io::Printer* printer,
                  "}\n\n");
 
   for (int i = 0; i < service->method_count(); ++i) {
-    PrintServerHandler(printer, service->method(i), vars);
+    PrintServerHandler(printer, service->method(i), vars, imports, import_alias);
   }
 
   printer->Print(*vars,
@@ -513,42 +535,53 @@ void PrintServer(google::protobuf::io::Printer* printer,
       "}\n\n");
 }
 
+bool IsSelfImport(const google::protobuf::FileDescriptor* self,
+                  const google::protobuf::FileDescriptor* import) {
+  if (GenerateFullGoPackage(self) == GenerateFullGoPackage(import)) {
+    return true;
+  }
+  return false;
+}
+
 void PrintMessageImports(
     google::protobuf::io::Printer* printer,
     const google::protobuf::FileDescriptor* file,
-    map<string, string>* vars) {
+    map<string, string>* vars,
+    set<string>* imports,
+    map<string, string>* import_alias) {
   set<const google::protobuf::FileDescriptor*> descs;
-  set<string> importedPkgs;
   for (int i = 0; i < file->service_count(); ++i) {
     const google::protobuf::ServiceDescriptor* service = file->service(i);
     for (int j = 0; j < service->method_count(); ++j) {
-      const google::protobuf::MethodDescriptor* method = service->method(i);
-      // Remove duplicated imports.
-      if (importedPkgs.find(
-          method->input_type()->file()->package()) == importedPkgs.end()) {
+      const google::protobuf::MethodDescriptor* method = service->method(j);
+      if (!IsSelfImport(file, method->input_type()->file())) {
         descs.insert(method->input_type()->file());
-        importedPkgs.insert(method->input_type()->file()->package());
       }
-      if (importedPkgs.find(
-          method->output_type()->file()->package()) == importedPkgs.end()) {
+      if (!IsSelfImport(file, method->output_type()->file())) {
         descs.insert(method->output_type()->file());
-        importedPkgs.insert(method->output_type()->file()->package());
       }
     }
   }
 
+  int idx = 0;
   for (auto fd : descs) {
-    if (fd->package() == (*vars)["PackageName"]) {
-      continue;
+    string pkg = GenerateFullGoPackage(fd);
+    if (pkg != "") {
+      auto ret = imports->insert(pkg);
+      // Use ret.second to guarantee if a package spans multiple files, it only
+      // gets 1 alias.
+      if (ret.second && file->package() == fd->package()) {
+        // the same package name in different directories. Require an alias.
+        (*import_alias)[pkg] = "apb" + std::to_string(idx++);
+      }
     }
-    string name = fd->name();
-    string import_path = "import \"";
-    if (name.find('/') == string::npos) {
-      // Assume all the proto in the same directory belong to the same package.
-      continue;
-    } else {
-      import_path += name.substr(0, name.find_last_of('/')) + "\"";
+  }
+  for (auto import : *imports) {
+    string import_path = "import ";
+    if (import_alias->find(import) != import_alias->end()) {
+      import_path += (*import_alias)[import] + " ";
     }
+    import_path += "\"" + import + "\"";
     printer->Print(import_path.c_str());
     printer->Print("\n");
   }
@@ -560,7 +593,8 @@ string GetServices(const google::protobuf::FileDescriptor* file) {
   google::protobuf::io::StringOutputStream output_stream(&output);
   google::protobuf::io::Printer printer(&output_stream, '$');
   map<string, string> vars;
-
+  map<string, string> import_alias;
+  set<string> imports;
   string package_name = !file->options().go_package().empty()
                             ? file->options().go_package()
                             : file->package();
@@ -578,7 +612,7 @@ string GetServices(const google::protobuf::FileDescriptor* file) {
       "\tproto \"github.com/golang/protobuf/proto\"\n"
       ")\n\n");
 
-  PrintMessageImports(&printer, file, &vars);
+  PrintMessageImports(&printer, file, &vars, &imports, &import_alias);
 
   // $Package$ is used to fully qualify method names.
   vars["Package"] = file->package();
@@ -587,9 +621,9 @@ string GetServices(const google::protobuf::FileDescriptor* file) {
   }
 
   for (int i = 0; i < file->service_count(); ++i) {
-    PrintClient(&printer, file->service(0), &vars);
+    PrintClient(&printer, file->service(0), &vars, imports, import_alias);
     printer.Print("\n");
-    PrintServer(&printer, file->service(0), &vars);
+    PrintServer(&printer, file->service(0), &vars, imports, import_alias);
     printer.Print("\n");
   }
   return output;