Abstract: A false target deceptive jamming method for countering UWB-SAR is proposed in this paper, which is based on dechirp processing to intercepted UWB-SAR signal , Doppler frequency modulation in phase domain and inverse dechirp to jamming signal. The jammer receiver quadrature downward converts and dechirps the intercepted UWB-SAR signal using an LFM oscillator, which could reduce the bandwidth and sample rate. And the jammer utilizes the Doppler frequency phase and backscattering coefficient template to modulate the intercepted narrowband signal. Then, the jammer uses LFM signal local oscillator to upward convert the jamming signal in order to recover the bandwidth of the jamming signal. The effects of parameter errors on the imaging position and resolution of false target in SAR image are also analyzed. Theoretical analysis and simulation indicated that the jamming signal proposed in this paper could produce a false target false. Even though the position of false target is offset and the resolution is reduce introduced by the reconnoitered parameters error, the jamming signal generated by the proposed method could still get a relatively clear image. Therefore, the proposed jamming signal generation method provides a feasible reference for countering UWB-SAR.