Abstract: Aiming at improving the utilization of polarimetric information,a new edge detector for polarimetric synthetic aperture radar(PoLSAR) images based on adaptive optimal polarimetric contrast enhancement and ratio of averaging was proposed in this paper.The optimal polarization is adaptive to window location and edge templates.Therefore the new method is robust.Experimental results of simulated and real PolSAR data both revealed that the performance of the new detector was improved.