Abstract: An ACJT group signature scheme with forward security is proposed in this paper.Based on the ACJT group signature scheme，forward security and revocation are improved.Forward security is achieved by an evolutional parameter，which is updated with the evolution of time segment，and the group public key and members’ certificates are updated along with the parameter.If a menber’s private key is betrayed，the attackers can’t forge the member’s previous signatures.Revocation is achieved by Certificate State List（CSL），which needs the group center to update the CSL in real time，and the previous signatures of the revocative members are still valid.The new scheme is highly secure and efficient.