Abstract: There is problem of channel congestion caused by the increased channel contention in satellite communication system with Packet Reservation Multiple Access (PRMA) protocol when the payload (amount of user terminals) goes up, and the long propagation delay worsens the situation with the result of increased packet drop rate. Considering that the requirement of the voice terminal for channel resource in different phase of communication progress is different, a new scheme of PRMA named PRMA-AC is proposed, which aims to decrease the channel contention and improve the quality of service by adopting an access control mechanism. Through theoretic analysis, the system model of the new scheme is given and performance parameters such as the access block probability and the packet drop probability are obtained. Finally, the scheme is compared with several other satellite PRMA protocols by simulation, and the result validates that the scheme is effective.