Abstract: In multi-privileged group communications,since users can access multiple data resources according to their different privileges,security issues become more difficult to solve than that in traditional group communications．Therefore,this paper proposed a novel centralized group key management scheme for multi-privileged environments．The proposed scheme employs multiway tree to construct a key graph and assigns a unique ID for every node in the key graph,so that the relationship between keys can be deduced by an ID which will contribute to locating the affected keys efficiently．As a result,the related users can update the affected keys through previous keys or with a rekeying material by using a one-way function when membership changes dynamically．Theoretical analysis and experimental simulation results show that the proposed scheme can reduce the storage and rekeying overhead efficiently,and it outperforms some previous schemes．Meanwhile,the forward and backward security is also guaranteed.