Abstract: The responsive deception for spaceborne SAR is studied and improved. The algorithm is got by analyzing the range domain and cross-range domain respectively. This algorithm provides high precision compress of cheat targets. And merely need the estimation of few radar parameters as:Dopppler frequency rate from the echoes, radar velocity and radar pulse repeat frequency. The demand of the precision of parameters is analyzed and the result shows that the request is little. The method of the estimation of Doppler frequency rate is worked out. The correctness of theoretic analyze and the validity of the algorithm are proved by computer simulation. The algorithm is of good signification for the theory and the practice of jamming signal production.