As users of network have become increasing, the supply of network-based services has activated and the necessity of a solution considering scale and speed of network for providing network-based services efficiently for users has been generated. A great deal of attention has been given recently to the concepts of the PBNM(Policy-Based Network Management) to accomplish these needs. This paper describes design and implementation of PDP(Policy Decision Point) in a policy-based network management system. The PDP provides role-based policy decision and distribution mechanisms. The role-based policy decision and distribution mechanisms allow an administrator manage and transmit policies by roles of devices without configuring each one of network devices manually. So, it provides the administrator with the convenience.