EXHIBIT 21

                                  SUBSIDIARIES

The following is a list of certain subsidiaries of USG Corporation as of
February 16, 2007, the principal names under which such subsidiaries do business
and the state or country in which each is organized. The list does not include
subsidiaries which would not, if considered in the aggregate as a single
subsidiary, have constituted a significant subsidiary within the meaning of Item
601(b)(21)(ii) of Regulation S-K as of December 31, 2006.



                                         ORGANIZED UNDER
NAME OF COMPANY                              LAWS OF
- ---------------                       ---------------------
                                   
United States Gypsum Company.......   Delaware
L&W Supply Corporation (a).........   Delaware
CGC Inc............................   New Brunswick, Canada


(a)  As of December 31, 2006, L&W Supply Corporation conducted its business at
     220 locations in the United States using various names registered under
     applicable assumed business name statutes.