This paper describes a method for the orthorectification of TerraSAR imagery. Being an effective earth observation technique, the synthetic aperture radar (SAR) systems supply extremely detailed radar images, day and night, under all weather conditions. EADS Astrium 's new radar satellite TerraSAR-X was launched in June 2007, which provides earth observation data of unprecedented quality, with a resolution of up to one meter and the error of orbit information up to 0.2 m, for increasingly diversified commercial as well as for scientific applications. This paper describes a method for the orthorectification of TerraSAR imagery. The correction method is based on a rigorous orbital/attitude model. The result from testing the method demonstrates the possibility to orthorectify TerraSAR imagery to sub-pixel accuracy. This research makes the well technique foundation of using high resolution satellite-borne SAR to update topographic map of scale 1:50,000 in Western China.