Dynamic extracting and processing of visual evoked potential(VEP) signals possess clinical importance. After processing of overlaying and averaging,VEP Signal acquired by hardware still has a large amount of background noises and is unable to be used in diagnosis directly. Concept,property and algorithm of wavelet transform-a newly developed timefrequency analysis for nonstationary signals are introduced in this paper. The authors extracted VEP signals from the background noises by wavelet transform success...