Attitude stability is a very important parameter for the platform design of Synthetic Aperture Radar(SAR) satellite. The mathematical expression of spaceborne SAR impulse response function with attitude jitter is studied using paired echo theory.The effect of attitude jitter on spaceborne SAR image qualities is summarized based on the theoretical analysis and computer simulation.The analytical mathematical expression is deduced

which is useful in analysis of attitude stability and SAR image qualities.A method for quantificationally analyzing attitude stability is proposed in this paper basing on the characteristics of SAR satellite.The conclusion is validated by large quantities of computer simulation according to the L

C and X-band SAR satellite parameters.It provides theoretical foundation for SAR satellite system analysis and design.