Abstract: A amplitude shift keying(ASK) demodulation method based on adaptive filtering was discussed in this paper. The demodulation and performance of adaptive demodulation method to ASK signals was studied by Least Mean Squares algorithm(LMS) in common use. Simulation results of computer indicated that the adaptive demodulation method had better performance than the traditional demodulation method, and it is easy to realize by digital singnal processing(DSP) technology.