Abstract: At present SAR polarimetric calibration algorithm are assumed to satisfy reciprocity fromdistributed targets.But not all distributed targets satisfy the principle of reciprocity.Aiming to solvethis problem,this paper presents a method to calibration based on reciprocity judgment of distributedtargets.According to the angle between the polarization scattering matrix and the reciprocal matrix ofeach pixel,we select pixels with small angle as the initial reciprocity calibration samples.Then,onthe basis of the coherence of targets,some pixels are selected as the final calibration samples.CECT-38X-band fully polarimetric data were completed by combining a typical calibration algorithm and se-lected distributed targets using the proposed method.Experiments show that this method,using dis-tributed targets,can be well applied to SAR polarimetric calibration.