diff --git a/CHANGELOG.md b/CHANGELOG.md
index 10ec3cf..eb7c9bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+2.2.0
+-----
+
+- Add option `config.length` for support change number chars.
+- Add option `config.strikethrough` for enable or disable strikethrough.
+
 2.1.3
 -----
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 3cfd9e2..3ca0fad 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    rucaptcha (2.1.4)
+    rucaptcha (2.2.0)
       railties (>= 3.2)
 
 GEM
@@ -142,4 +142,4 @@ DEPENDENCIES
   rucaptcha!
 
 BUNDLED WITH
-   1.14.5
+   1.15.4
diff --git a/README.md b/README.md
index 5317ff5..897b43a 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ This is a Captcha gem for Rails Applications which generates captcha image by C
 - High performance.
 
 ## Usage
+
 Put rucaptcha in your `Gemfile`:
 
 ```
@@ -41,10 +42,10 @@ RuCaptcha.configure do
   # 默认：会从 Rails 配置的 cache_store 里面读取相同的配置信息，并尝试用可以运行的方式，用于存储验证码字符
   # 但如果是 [:null_store, :memory_store, :file_store] 之类的，你可以通过下面的配置项单独给 RuCaptcha 配置 cache_store
   self.cache_store = :mem_cache_store
-  # 验证码长度 length, 默认是 5, allows: [3,4,5,6,7]
+  # Chars length, default: 5, allows: [3 - 7]
   # self.length = 5
-  # 验证码横线 line, 默认显示横线, default: true, allows: [true, false], 设置为false时, 横线不是显示, 验证码识别度高.
-  # self.line = true
+  # enable/disable Strikethrough.
+  # self.strikethrough = true
 end
 ```
 
diff --git a/Rakefile b/Rakefile
index 3c74416..ed51560 100644
--- a/Rakefile
+++ b/Rakefile
@@ -13,6 +13,6 @@ task default: :spec
 task :preview do
   require 'rucaptcha'
 
-  res = RuCaptcha.create(1)
+  res = RuCaptcha.create(1, 3, 1)
   puts res[1]
-end
\ No newline at end of file
+end
diff --git a/lib/rucaptcha.rb b/lib/rucaptcha.rb
index c89c51f..8bd18c4 100644
--- a/lib/rucaptcha.rb
+++ b/lib/rucaptcha.rb
@@ -15,10 +15,11 @@ module RuCaptcha
     def config
       return @config if defined?(@config)
       @config = Configuration.new
-      @config.style       = :colorful
-      @config.length    = 5
-      @config.line    = true
-      @config.expires_in  = 2.minutes
+      @config.style         = :colorful
+      @config.length        = 5
+      @config.strikethrough = true
+      @config.expires_in    = 2.minutes
+
       if Rails.application
         @config.cache_store = Rails.application.config.cache_store
       else
@@ -35,9 +36,13 @@ module RuCaptcha
     def generate()
       style = config.style == :colorful ? 1 : 0
       length = config.length
-      raise Rucaptcha::Errors::Configuration, 'length config error, value must in 3..7' unless length.in?(3..7)
-      line = config.line ? 1 : 0
-      self.create(style, length, line)
+
+      unless length.in?(3..7)
+        raise Rucaptcha::Errors::Configuration, 'length config error, value must in 3..7'
+      end
+
+      strikethrough = config.strikethrough ? 1 : 0
+      self.create(style, length, strikethrough)
     end
 
     def check_cache_store!
diff --git a/lib/rucaptcha/configuration.rb b/lib/rucaptcha/configuration.rb
index 9b383c4..d7dcb32 100644
--- a/lib/rucaptcha/configuration.rb
+++ b/lib/rucaptcha/configuration.rb
@@ -7,10 +7,9 @@ module RuCaptcha
     attr_accessor :expires_in
     # Color style, default: :colorful, allows: [:colorful, :black_white]
     attr_accessor :style
-    # Captcha Digits: default 5, allows: [3,4,5,6,7]
+    # Chars length: default 5, allows: [3..7]
     attr_accessor :length
-    # rucaptcha line, default: true, allows: [true, false]
-    attr_accessor :line
-
+    # strikethrough, default: true
+    attr_accessor :strikethrough
   end
 end
diff --git a/lib/rucaptcha/version.rb b/lib/rucaptcha/version.rb
index 3adafbc..c090ace 100644
--- a/lib/rucaptcha/version.rb
+++ b/lib/rucaptcha/version.rb
@@ -1,3 +1,3 @@
 module RuCaptcha
-  VERSION = '2.1.4'
+  VERSION = '2.2.0'
 end
diff --git a/spec/captcha_spec.rb b/spec/captcha_spec.rb
index 41a9bd4..4a6c3a3 100644
--- a/spec/captcha_spec.rb
+++ b/spec/captcha_spec.rb
@@ -82,14 +82,14 @@ describe RuCaptcha do
       expect(res[1]).not_to eq(nil)
     end
 
-    it 'should work with line true' do
+    it 'should work with strikethrough enable' do
       res = RuCaptcha.create(1, 7, 1)
       expect(res.length).to eq(2)
       expect(res[0].length).to eq(7)
       expect(res[1]).not_to eq(nil)
     end
 
-    it 'should work with line false' do
+    it 'should work with strikethrough disable' do
       res = RuCaptcha.create(1, 7, 0)
       expect(res.length).to eq(2)
       expect(res[0].length).to eq(7)