Abstract: The conventional characteristics analysis methods for moving target in Frequency Modulation Continuous Wave (FMCW) SAR all carry out in space-domain, leading to approximated and partial results. Therefore, a novel analysis approach based on an accurate two-dimensional spectrum is proposed in the paper. The approach takes accurately the continuous movements of antenna and moving targets during pulse transmission and reception into account and derives an analytical slant range model for moving targets in FMCW SAR, as well as an accurate two-dimensional spectrum. Based on the spectrum, the characteristics of moving target are discussed in detail, including the effects caused by 2-D velocities of moving target. Compared with its counterparts, it is more accurate and robust. Simulation experiments verify the reasonableness and effectiveness of the proposed method.