Fibroblast cell culture was performed to evaluate cell adhesion and cell morphology on novel hydrolyzable copolymers composed of poly(D,L-lactic acid) (PDLA) macromonomer, 2-methacryloyloxyethyl phosphorylcholine (MPC), and n-butyl methacrylate. The copolymers were used as cell culture materials for regulating the interaction between the cells and the polymer surface. The results of X-ray photoelectron spectroscopy (XPS) confirmed that the PDLA chains and MPC units were present in the copolymer coating on PET films. Cell adhesion and morphology of adherent cells on coatings of the copolymers were studied. The number of cells on the surface increased with the PDLA content of the copolymer. As for the cell morphology, a round shape was observed on copolymers containing MPC units. These findings suggest that the cells recognize the PDLA and MPC units on the surface via changes in protein adsorption and/or conformation, and that the numbers of adhering cells and the cell morphology can be regulated by the composition of the copolymer.