Abstract: To improve the low velocity resolution of VSAR system and decrease the number of antennas, and to detect slowly moving targets with VSAR system, the Burg spectrum method was used in signal processing of VSAR system instead of conventional DFT method to extract the velocity distribution. Using the Burg method can achieve the higher velocity resolution and the higher azimuth resolution than using the conventional spectral estimate. It can decrease the number of antennas and the total length of the array.