As a large quantity of information is presented in XML format on the web, there are increasing demands for XML security. until now research on XML security has been focused on the security of data communication using digital signatures or encryption technologies. As n data become extensive and complex, however, XML security comes to involve not only communication security but also managerial security. Managerial security is guaranteed through access control. In this paper, we introduces results of former study of access control for XML document and propose further study problems. First, we present the need of access control for XML documents and basic elements of model. And we look around research trend of access control system last, we analyze further problems of access control for XML documents.