Abstract: A series of experiments was carried out to investigate the nature and the difference between the normal and burned skin extracts from human （HNSE and HBSE） and rat （RNSE and RBSE）. Immunochemical analysis including immuno-diffusion test, rocket immunoelectrophoresis, and ELISA were performed. The results showed that:（1） the antigenicity of burned skin was stronger than that of normal skin;（2）the extracts of burned skin composed of a very high specificity as compared with the normal skin and there was very little crossreactivity between them. Our data indicate that the antigenicity of HNSE and HBSE as well as that of RNSE and RBSE is quite different, and thus these substances may be very discrepant in nature.