Abstract: Blend films were successfully prepared by heterocoagulation blending natural rubber latex (NRL) and soybean protein chitosan conjugations prepared by a dry heat reaction of soybean protein isolate (SPI) and chitosan (CHI). The covalent attachment of SPI and CHI was confirmed by the change of the particle size distribution. The surface morphology, mechanical property, and water soluble protein (WSP) of films were characterized. The results showed that the compound film was endowed with improved smoothness, flatness, denseness, and mechanical property and reduced WSP which should have a broaden applications in medical film materials.