Abstract: The traditional bandwidth allocation schemes are based on layered design.They just solve the problem at date link layer only and don’t consider the variable channel state and the Quality of Service（QoS） of traffic flows which will influence the performance of bandwidth allocation scheme seriously.This paper proposes a cross-layer bandwidth allocation scheme for the satellite network which supports the transmission of voice traffic and Internet data.This scheme binds the application layer’s characteristic of traffic,the data link layer’s decisions on the bandwidth allocation,with the physical layer’s channel state in a cross-layer optimization.The master station computes a cost function that considers all the relevant parameters and gets the most efficiency bandwidth assignments through dynamic programming algorithm.Numerical results show that this cross-layer bandwidth allocation scheme can adapt to the variable channel state.Moreover,this scheme increases the goodput of Internet data as much as possible without deteriorating the QoS of voice traffic.