This paper presents the moving target focusing method, whichallows focusing moving targets in complex synthetic aperture radar(SAR) images without raw data. The method is developed on the rangemigration algorithm, where focusing moving target is an interpolationstep in the wave domain. The simulated results are provided in thepaper to illustrate the proposed method whereas the experimentalresults show its practicality. The method can be flexibly applied fromsmall area to the whole SAR scene.