This paper introduces a Ku-band car-borne frequency modulated continuous wave synthetic aperture radar (FMCW SAR) system in order to acquire clear images in stripmap mode. The specification and the architecture of the system are provided to demonstrate the outstanding performance. The conventional range doppler algorithm(RDA) is modified to be suitable for the radar system equipped in an automobile. After gathering raw data on the highway and signal processing, the effectiveness of the radar to get SAR images is verified in the practical results.