To find out which biomaterial had the best biocompatibility, we compared the acute phase reaction of common biomaterials preparing for vascular grafts with the material of polyurethane modified by silk fibroin (SF-PU(1:1)). After transplanted the materials of dacron, polyterafluoroethylene (e-PTFE), polyurethane (PU), SF-PU(1:1) in rat muscle for one week, we studied the influence of different biomaterials on the tissue compatibility by using rat acute toxicity test, test of local reaction in muscle, tissue section staining, WBC and PLT count. As a result, dacron had the worst tissue compatibility. The other biomaterials had slight local inflammatory reaction. The WBC and PLT was nearly the same with the blank except dacron. e-PTFE, pure PU and SF-PU(1:1) had the better tissue compatibility than traditional dacron. Especially SF-PU(1:1) had the best tissue compatibility. Because of the better physical properties and tissue compatibility of SF-PU(1:1), the prospect of preparing small-diameter vascular grafts with SF-PU was cheerful.