As the distribution rate of smart device increases, users of smartwork are increasingly able to work without constraints imposed by time and space. However, there are many security threats in smartwork environment. Security threats is illegal information for an unauthenticated device. Especially, smartwork environment is approach to users. Therefore, there are other matters concerning justifiable user and device authentication. However, the studies of smartwork are still in early stage of development, and the studies of user and device authentication also not enough to apply smartwork environment. In this paper, we proposed USIM based user and device authentication scheme in the smartwork environment.