From the principle of linear RD algorithm and mod el of airborne spotlight SAR, this paper studies airborne spotlight SAR geolocat ion accuracy. Firstly, the effect of the radar parameters on th e airborne SAR geolocation accuracy is analyzed, and these parameters are mostly platform moti on errors from t he onboard GPS and INS devices. Then, the formulas of airborne spotlight SAR g eolocation errors are given. Finally, simulation results and experimental result s using th e data collected by an experimental airborne SAR are employed to verify the prop osed analysis approach. This paper provides useful reference for the design of the geolocation accuracy of airborne SAR system.