Abstract: Detailed performance evaluation was presented with respect to the channel number,combining mode,packet loss ratio and transmission delay of multi-channel stop-and-wait ARQ associated with packet combining over a Rayleigh fading channel.The analysis results show that,to achieve optimal system performance,the number of parallel ARQ channels should be planned according to the packet transmission time and round trip feedback delay etc.;the processing delay in the receiver could be decreased by choosing an appropriate combining scheme according to channel quality;and steady transmission delay and throughput could be achieved by adjusting the maximum number of ARQ retransmissions according to the packet loss ratio and channel quality.