The surface of polydimethylsiloxane rubber (PDMS) was irradiated by a CO2-pulsed laser. The irradiated surfaces were grafted by hydroxyethylmethacrylate phosphatidylcholine (HEMAPC) by using the preirradiation method. The laser-treated surfaces and HENIAPC-grafted PDMS surfaces were characterized by using a variety of techniques including ATR-FTIR spectroscopy, scanning electron microscopy (SEM), and wettability, which was measured by a water-drop contact angle. Different surfaces with different wettability were prepared. These surfaces, including untreated PDMS (hydrophobic), laser-treated PDMS (superhydrophobic), and HEMAPC-grafted surfaces (superhydrophilic), were used for a platelet adhesion study. Results from in vitro testing indicated that chemical structures, such as negative-charge polar groups and wettability, are important factors in blood compatibility of these surfaces and the superhydrophilic (the most wettable) and the superhydrophobic (the most unwettable) of modified PDMS surfaces have excellent blood compatibility compared to the unmodified PDMS. (C) 2003 Wiley Periodicals, Inc.