IETF (Internet Engineering Task Force) has proposed a PMIPv6 (Proxy Mobile IPv6) to make up for the weak points caused by handoff delay and signaling overhead. The handoff delay and signaling overhead occur due to frequent binding updates during handoff in the MIPv6 (Mobile IPv6). Although the handoff in the PMIPv6 can be faster than that in the MIPv6, there still exists the handoff delay and packet loss during the handoff. For these reasons, the researches to reduce the handoff delay and retransmit missing packets have been investigated. We propose a scheme in order to set up the multicast group. As a result, the scheme reduces the handoff delay by using the cache and prevents the packet loss in the PMIPv6. We have analyzed general handoff performance in the PMIPv6 and packet loss occurring interval from a practical point of view to verify the proposed scheme.