The explosive growth of the Web, the increasing popularity of PCs and the advances in high-speed network access have brought distributed computing into the mainstream. To simplify network programming and to realize componentbased software architecture, distributed object models have emerged as standards. One of those models is distributed component object model (DCOM) which is a protocol that enables software components to communicate directly over a network in a reliable, and e cient manner. In this paper, we investigate an aspect of DCOM concerning software architecture and security mechanism. Also, we describe the concept of role-based access control (RBAC) which began with multi-user and multi-application on-line systems pioneered in the 1970s. And we investigate how we can enforce the role-based access control as a security provider within DCOM, specially in access security policy. Ó