diff --git a/lib/Cli.rb b/lib/Cli.rb
index 136cba1..2b53ab3 100644
--- a/lib/Cli.rb
+++ b/lib/Cli.rb
@@ -14,6 +14,8 @@ require "#{APP_ROOT}/lib/MPW.rb"
 class Cli
 
 	# Constructor
+	# @args: lang -> the operating system language
+	#        config_file -> a specify config file
 	def initialize(lang, config_file=nil)
 		@m = MPW.new(config_file)
 		
diff --git a/lib/MPW.rb b/lib/MPW.rb
index e4c2fd3..d0588d7 100644
--- a/lib/MPW.rb
+++ b/lib/MPW.rb
@@ -25,6 +25,7 @@ class MPW
 	attr_accessor :timeout_pwd
 
 	# Constructor
+	# @args: file_config -> the specify config file
 	def initialize(file_config=nil)
 		@error_msg  = nil
 		@file_config = "#{Dir.home()}/.mpw.cfg"
@@ -86,12 +87,7 @@ class MPW
 				return false
 			end
 				
-			if !@lang.nil? && !@lang.empty?
-				if !File.exist?("#{APP_ROOT}/i18n/#{@lang}.yml")
-					@lang = 'en'
-				end
-				I18n.locale = @lang.to_sym
-			end
+			I18n.locale = @lang.to_sym
 
 		rescue Exception => e 
 			@error_msg = "#{I18n.t('error.config.check')}\n#{e}"
diff --git a/mpw b/mpw
index 2aacb50..a06fd40 100755
--- a/mpw
+++ b/mpw
@@ -15,10 +15,9 @@ require "#{APP_ROOT}/lib/Cli.rb"
 
 lang = Locale::Tag.parse(ENV['LANG']).to_simple.to_s[0..1]
 
-if !File.exist?("#{APP_ROOT}/i18n/#{lang}.yml")
-	lang = 'en'
-end
+I18n::Backend::Simple.send(:include, I18n::Backend::Fallbacks)
 I18n.load_path = Dir["#{APP_ROOT}/i18n/*.yml"]
+I18n.default_locale = :en
 I18n.locale = lang.to_sym
 
 options = {}
diff --git a/mpw-ssh b/mpw-ssh
index a67e134..a991cc1 100755
--- a/mpw-ssh
+++ b/mpw-ssh
@@ -14,13 +14,11 @@ require "#{APP_ROOT}/lib/CliSSH.rb"
 
 lang = Locale::Tag.parse(ENV['LANG']).to_simple.to_s[0..1]
 
-if !File.exist?("#{APP_ROOT}/i18n/#{lang}.yml")
-	lang = 'en'
-end
+I18n::Backend::Simple.send(:include, I18n::Backend::Fallbacks)
 I18n.load_path = Dir["#{APP_ROOT}/i18n/*.yml"]
+I18n.default_locale = :en
 I18n.locale = lang.to_sym
 
-
 options = {}
 OptionParser.new do |opts|
 	opts.banner = "#{I18n.t('ssh.option.usage')}: mpw-ssh SEARCH [options]"