Abstract: A new evaluation method is proposed to analyze the frequency-domain characteristics of high-speed analog to digital converter(ADC).The new method uses incoherent sampling,and adopts the window-added and interpolated measurements based on the standard fast discrete Fourier transform to reduce spectral leakage and to improve evaluation precision, and can reduce as greatly as possible the difficulties and cost in constructing the evaluation system.The behavioral dynamic model of actual high-speed ADC is employed and computer simulation is made to validate the effectiveness of the presented method.