A dynamic policy based network management scheme is presented for the problem that traditional policies can??t preferably adapt to change of network state. It defined dynamic policy form and appended new module PMA to IETF policy frame to improves the adaptability of policie. Then the application of dynamic policy to allocate resource is presented. By experiment and analysis, it is shown that this scheme insures new call blocking probability, reduces handoff call dropping probability and increases network resource utilizing rate effectively.