Video communication with Quality of Service (QoS) is an important and challenging task. The transmitted video stream must be able to afford the bandwidth variance and unavoidable packet loss in the Internet. In particular, fmegranular-scalability (FGS) video coding has been adopted by the MPEG4 standard as the awe videoxompression method for streaming applications. In this paper, we use unequal loss protection (ULP) to protect FGS compressed video, and under the restriction of the network bandwidth, joint sourcexhannel ratedistortion based optimization is performed in bit allocation to minimize the end-to-end distortion. Simulation results demonstrate effectiveness of our approach.