It's difficult that apply composite skin to clinicat present. One of reasons is uncertain resultabout decreasing or eliminating its antigen, so we continue do animal experiments, and used Wistar rats as donor, SD rats as receptor to do skin grafting, in order to judge that the antigen abouttwo kinds of rats whether is same or not. We observe the survival rate of grafting flap, histological changes, proliferation function of lymphocyte on POstoperation. The results showed that allo flaps grafted were rejected completely, so the MHC 11 antigen is different between two kinds ofrats. Its gene were not contaminated, and can be used as the reliable model of composite skin.