Abstract: To study high-rate compression about airborne SAR,this paper proposes an SAR image compressing strategy which extracts and protects the target region based on structure component.Firstly,the SAR image is decomposed into structure component and texture component.Then the target information is detected and classified from the structure component to construct ROI mask.Finally,the ROI(region-of-interest) mask is used to protect the important target information by allocating more bits while the residual allocating less when compressing.The experimental results indicate that the reconstructed image of the proposed approach has better visual effect than that of JPEG2000 arithmetic under the same bit rate.