Abstract: In order to obtain high range resolution, wideband or ultra wideband waveform are used to radar system, which makes great trouble for data collection. Since the limitation of A/D technology is a bottleneck in the implementation, A/D sampling rate must be lowered. For Chirp waveform, dechirp provides the ability to alleviate the A/D problem by easing the requirement on the sampling rate and reduce the quantity of data. In this paper, dechirp is applied to Synthetic Aperture Radar, and furthermore, both the imaging steps and simulation results, which validate the method, are presented.