A series of random and block copolymers composed of hydrophilic and hydrophobic monomer units have been synthesized by the free and living radical polymerization methods, respectively. The hydrophilic monomer unit, 2-methacryloyloxyethyl phosphorylcholine (MPC), was selected because the MPC polymers are well-known for their excellent bio- and blood compatibilities. The semi-fluorinated monomer, 2,2,2-trifluoroethyl methacrylate (TFEMA), was used as the hydrophobic monomer unit. Several analyses of the copolymer surface showed that the TFEMA unit was concentrated at the outermost surface on the random copolymer surface and characteristics of MPC unit was dominant on the block copolymer with a low-MPC-unit composition in the dry state. A reorientation of the MPC unit occurred dynamically in the wet state because of the strong hydrophilicity of the MPC units. In the case of the block copolymer with a low-MPC-unit composition, the surface was covered with the MPC units in the wet state. As a result, the amount of the adsorbed bovine plasma fibrinogen and bovine serum γ-globulin on the block copolymer surface was reduced dramatically.