To improve the hemocompatibility and biocompatibility of polyurethanes (PUs), PU surface was firstly modified by poly(ethylene glycol) PEG through acryloyl chloride and subsequently grafted on carboxymethyl-chitosan (CMCS). Attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis confirmed that carboxyl-chitosan was grafted onto PUs surface. The surface properties of unmodified and modified PU films were determined and compared by water contact angle assessment. After PEG and CMCS grafting, the surface energy of the PU film was increased. Furthermore, the hemocompatibility of the modified PU films was systematically evaluated by bovine serum albumin (BSA) adsorption, the dynamic blood clotting test, the platelet adhesion test, and the hemolytic test. It appears that BSA adsorption and platelet adhesion were significantly curtailed for the modified PU films. Therefore, the obtained results showed the modified PU film has better hemocompatibility. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012