diff --git a/autoload/SpaceVim/layers/lang/c.vim b/autoload/SpaceVim/layers/lang/c.vim
index 08c458c5f..58a5679bc 100644
--- a/autoload/SpaceVim/layers/lang/c.vim
+++ b/autoload/SpaceVim/layers/lang/c.vim
@@ -1,7 +1,40 @@
 ""
 " @section Layer_lang_c
 "   this layer provide c family language code completion and syntax chaeck.you
-"   need install clang.
+"   need install clang. 
+"
+" configuration:
+"
+"   1.setting compile flag: 
+" >
+"   let g:deoplete#sources#clang#flags = ['-Iwhatever', ...]
+" <
+"   2.`g:deoplete#sources#clang#executable` sets the path to the clang
+"   executable.
+"
+"   3.`g:deoplete#sources#clang#autofill_neomake` is a boolean that tells this
+"   plugin to fill in the `g:neomake_<filetype>_clang_maker` variable with the
+"   clang executable path and flags. You will still need to enable it with
+"   `g:neomake_<filetype>_enabled_make=['clang']`.
+"
+"   4.`g:deoplete#sources#clang#std` is a dict containing the standards you want
+"   to use. It's not used if you already have `-std=whatever` in your flags. The
+"   defaults are:
+" >
+"   {
+"       'c': 'c11',
+"       'cpp': 'c++1z',
+"       'objc': 'c11',
+"       'objcpp': 'c++1z',
+"   }
+" <
+"   5.`g:deoplete#sources#clang#preproc_max_lines` sets the
+"   maximum number of lines to search for a #ifdef or #endif
+"   line. #ifdef lines are discarded to get completions within
+"   conditional preprocessor blocks. The default is 50, setting it to 0 disables this feature.
+"
+
+
 
 function! SpaceVim#layers#lang#c#plugins() abort
     let plugins = []
@@ -14,5 +47,5 @@ function! SpaceVim#layers#lang#c#plugins() abort
 endfunction
 
 function! SpaceVim#layers#lang#c#config() abort
-    
+
 endfunction
diff --git a/doc/SpaceVim.txt b/doc/SpaceVim.txt
index 439b00d85..29559ce20 100644
--- a/doc/SpaceVim.txt
+++ b/doc/SpaceVim.txt
@@ -425,6 +425,37 @@ LAYER_LANG_C                                           *SpaceVim-layer_lang_c*
   this layer provide c family language code completion and syntax chaeck.you
 need install clang.
 
+configuration:
+
+  1.setting compile flag:
+>
+  let g:deoplete#sources#clang#flags = ['-Iwhatever', ...]
+<
+  2.`g:deoplete#sources#clang#executable` sets the path to the clang
+executable.
+
+  3.`g:deoplete#sources#clang#autofill_neomake` is a boolean that tells this
+plugin to fill in the `g:neomake_<filetype>_clang_maker` variable with the
+clang executable path and flags. You will still need to enable it with
+`g:neomake_<filetype>_enabled_make=['clang']`.
+
+  4.`g:deoplete#sources#clang#std` is a dict containing the standards you want
+to use. It's not used if you already have `-std=whatever` in your flags. The
+defaults are:
+>
+  {
+      'c': 'c11',
+      'cpp': 'c++1z',
+      'objc': 'c11',
+      'objcpp': 'c++1z',
+  }
+<
+  5.`g:deoplete#sources#clang#preproc_max_lines` sets the   maximum number of
+lines to search for a #ifdef or #endif   line. #ifdef lines are discarded to
+get completions within   conditional preprocessor blocks. The default is 50,
+setting it to 0 disables this feature.
+
+
 ==============================================================================
 LAYER-LANG-RUST                                     *SpaceVim-layer-lang-rust*