Abstract: A new application of the ambiguity function is given in this paper to resolve the problem of moving targets imaging of SAR.It is well known that the SAR echo can be considered as a linear FM signal,so does the echo of moving targets.The square modulus of linear FM signal has high energy centrality in the ambiguity domain.Its peaks represent straight lines whose slopes equal to the Doppler rates of the moving targets echo signals.The parameters of moving targets can be estimated by applying the Radon transform to the ambiguity function.In this way,the moving targets can be easily detected and imaged.The simulation results prove the effectiveness and feasibility of this new method.