It has been well known that fluorinated polyurethanes exhibit unique low surface energy, biocompatibility, biostability and nonsticking behavior. Consequently, these polymers have attracted considerable interest. In this study, the effect of various concentrations of fluorinated polyurethanes in the polyurethanes on the surface structures of the blends and their hemocompatibility were investigated by XPS, AFM, contact angle and platelet adhesion. It was found that the high concentration fluorine on the outer surfaces of the blends obtained with the low concentration of fluorinated polyurethanes (F: 0.342 wt%) in the blends was the same as that of the fluorinated poly(ether urethane)s, and all of the blends and the fluorinated poly(ether urethane)s had good hemocompatibility, compared with poly(ether urethane)s. The polymer blends and fluorinated poly(ether urethane)s suppressed platelet adhesion due to their high hydrophobicity and low surface tension. The XPS, AMF and contact angle results indicated that the high hydrophobicity of outer surface of the polyurethane blends is independent of the fluorinated polyurethanes content in the polymer blends but related to the concentration of the CF3 groups because the lower critical surface tensions and higher contact angle of many fluorinated surfaces reflect the concentration of CF3 groups.