Abstract: Objective To prepare and evaluate the biocompatibility of carbon nanotubes-polyurethane composite. Method multiwalled carbon nanotubes were introduced into a polyurethane elastomer through a lab developed process of sol-gel. The biocompatibilities including cytotoxcicity, tissue compatibility, hemolysis, dynamic coagulation time, and platelets activation have been evaluated according to the guideline of ISO10993. The tensile strength and elongation rate of the composite were also tested. Result Experimental results indicated that the composite remained the excellent mechanical property of polyurethane; meanwhile, there was no cytotoxicity observed with fibroblasts, inflammation was obvious lighter, and platelets activation was significantly decreased. Conclusion A new composite of carbon nanotube-polyurethane were obtained and its biocompatibility was improved notably.