Abstract: In this paper,based on the studied time and space variant characteristics of oceansound channel,the channel response function is found by adaptive filtering.The obtained channel's response function is applied to perform the match for the channel and satisfactory effect isshown.The key problem is how to increase the convergent speed of adaptive iteration algorithm.For this purpose,besides using an adaptive step size factory and performing adaptive filtering inthe frequency domain,a rational choice of weight's parameter (the number of weights and thetime relationship between weights) is proposed.The result of this study shows that under thecondition of rational choice of weight parameter a complicated response function of channel canbe expressed by a few number of weights.