Bio-inspired phosphorylcholine modification on material surface has shown great promise in constructing biocompatible materials. In this study, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) was grown on poly(ε-caprolactone) (PCL) surface in order to suppress protein adsorption and cells adhesion and to improve blood compatibility. The initiator for surface initiated atom transfer radical polymerization (SI-ATRP) was covalently tethered on PCL surface and then PMPC brushes with diverse graft amounts were grafted to PCL film. X-ray photoelectron spectroscopy (XPS) and water contact angle measurement were used to characterize the modified sheets. The PMPC-grafted PCL sheets showed lower protein adsorption, maintained secondary structure of detached protein, and suppressed adhesion and pseudopodium formation of the platelets, along with keeping longer activated partial thromboplastin time (APTT) in comparison with PCL membranes. At the same time, PMPC-grafted PCL sheets suppressed the LO2 cells adhesion. These results showed that phosphorylcholine SI-ATRP modification on PCL surface may provide PCL more biocompatible in biomaterial applications.