diff --git a/autoload/emmet.vim b/autoload/emmet.vim
index 0985aa3..3da7424 100644
--- a/autoload/emmet.vim
+++ b/autoload/emmet.vim
@@ -1,11 +1,13 @@
 "=============================================================================
 " emmet.vim
 " Author: Yasuhiro Matsumoto <mattn.jp@gmail.com>
-" Last Change: 28-Nov-2013.
+" Last Change: 06-Dec-2013.
 
 let s:save_cpo = &cpo
 set cpo&vim
 
+let s:filtermx = '|\(\%(bem\|html\|haml\|slim\|e\|c\|fc\|xsl\|t\|\/[^ ]\+\)\s*,\{0,1}\s*\)*$'
+
 function! emmet#getExpandos(type, key)
   let expandos = emmet#getResource(a:type, 'expandos', {})
   if has_key(expandos, a:key)
@@ -463,10 +465,9 @@ function! emmet#expandAbbr(mode, abbr) range
     if len(leader) == 0
       return ''
     endif
-    let mx = '|\(\%(html\|haml\|slim\|e\|c\|fc\|xsl\|t\|\/[^ ]\+\)\s*,\{0,1}\s*\)*$'
-    if leader =~ mx
-      let filters = map(split(matchstr(leader, mx)[1:], '\s*[^\\]\zs,\s*'), 'substitute(v:val, "\\\\\\\\zs.\\\\ze", "&", "g")')
-      let leader = substitute(leader, mx, '', '')
+    if leader =~ s:filtermx
+      let filters = map(split(matchstr(leader, s:filtermx)[1:], '\s*[^\\]\zs,\s*'), 'substitute(v:val, "\\\\\\\\zs.\\\\ze", "&", "g")')
+      let leader = substitute(leader, s:filtermx, '', '')
     endif
     if leader =~ '\*'
       let query = substitute(leader, '*', '*' . (a:lastline - a:firstline + 1), '')
@@ -573,10 +574,9 @@ function! emmet#expandAbbr(mode, abbr) range
       let rest = getline('.')[len(line):]
     endif
     let str = part
-    let mx = '|\(\%(html\|haml\|slim\|e\|c\|fc\|xsl\|t\|\/[^ ]\+\)\s*,\{0,1}\s*\)*$'
-    if str =~ mx
-      let filters = split(matchstr(str, mx)[1:], '\s*,\s*')
-      let str = substitute(str, mx, '', '')
+    if str =~ s:filtermx
+      let filters = split(matchstr(str, s:filtermx)[1:], '\s*,\s*')
+      let str = substitute(str, s:filtermx, '', '')
     endif
     let items = emmet#parseIntoTree(str, rtype).child
     for item in items
@@ -784,15 +784,14 @@ function! emmet#codePretty() range
 endfunction
 
 function! emmet#expandWord(abbr, type, orig)
-  let mx = '|\(\%(html\|haml\|slim\|e\|c\|fc\|xsl\|t\|\/[^ ]\+\)\s*,\{0,1}\s*\)*$'
   let str = a:abbr
   let type = a:type
   let indent = emmet#getIndentation(type)
 
   if len(type) == 0 | let type = 'html' | endif
-  if str =~ mx
-    let filters = split(matchstr(str, mx)[1:], '\s*,\s*')
-    let str = substitute(str, mx, '', '')
+  if str =~ s:filtermx
+    let filters = split(matchstr(str, s:filtermx)[1:], '\s*,\s*')
+    let str = substitute(str, s:filtermx, '', '')
   else
     let filters = emmet#getFilters(a:type)
     if len(filters) == 0
diff --git a/autoload/emmet/lang/html.vim b/autoload/emmet/lang/html.vim
index 844360d..d861cfd 100644
--- a/autoload/emmet/lang/html.vim
+++ b/autoload/emmet/lang/html.vim
@@ -1,6 +1,6 @@
 let s:mx = '\([+>]\|[<^]\+\)\{-}\s*'
 \     .'\((*\)\{-}\s*'
-\       .'\([@#.]\{-}[a-zA-Z\!][a-zA-Z0-9:_\!\-$]*\|{\%([^$}]\+\|\$#\|\${\w\+}\|\$\+\)*}*[ \t\r\n}]*\)'
+\       .'\([@#.]\{-}[a-zA-Z_\!][a-zA-Z0-9:_\!\-$]*\|{\%([^$}]\+\|\$#\|\${\w\+}\|\$\+\)*}*[ \t\r\n}]*\)'
 \       .'\('
 \         .'\%('
 \           .'\%(#{[{}a-zA-Z0-9_\-\$]\+\|#[a-zA-Z0-9_\-\$]\+\)'
@@ -386,6 +386,30 @@ function! emmet#lang#html#toString(settings, current, type, inline, filters, ite
         endwhile
         let attr = substitute(attr, '\$$', itemno+1, '')
       endif
+      if attr == 'class' && emmet#useFilter(filters, 'bem')
+        let vals = split(Val, '\s\+')
+        let Val = ''
+        let lead = ''
+        for _val in vals
+          if len(Val) > 0
+            let Val .= ' '
+          endif
+          if _val =~ '^\a_'
+            let lead = _val[0]
+            let Val .= lead . ' ' .  _val
+          elseif _val =~ '^_'
+            if len(lead) == 0
+              let pattr = current.parent.attr
+              if has_key(pattr, 'class')
+                let lead = pattr['class']
+              endif
+            endif
+            let Val .= lead . ' ' . lead . _val
+          else
+            let Val .= _val
+          endif
+        endfor
+      endif
       let str .= ' ' . attr . '=' . q . Val . q
       if emmet#useFilter(filters, 'c')
         if attr == 'id' | let comment .= '#' . Val | endif