In this paper, we suggests an more efficient overlay multicast key management scheme than existing schemes. If a new member joins a clusters, it will establish a separate secure channel with its cluster leader using a temporal key. Using this method, we eliminate the need to update key for other members in the session. After a member leaves, only one renewal in its cluster is required to ensure forward confidentiality. In proposed scheme, each message is encrypted/decrypted once for all members because cluster leaders used the cluster key(CK) that is used for communication between clusters. also, this scheme involves merging and splitting, it is not only efficient group management but also key management.