Abstract: Aim To study the LDPE surface heparinization with plasma initiation technique, and antithrombogenicity and tissue compatibility of heparinizing LDPE surface.Methods\ The LDPE films were grafted with PEG and heparin by plasma initiation technique. The biocompatibility of the modified LDPE surfaces was discussed by blood coagulation time in vitro and cell growth test. Results\ Using Ar plasma initiation method PEG and heparin could be attached to the LDPE surface. Water contact angle of LDPE modified with heparin was decreased. Surface free energy and hydrophilicity was increased. APTT and TT of the LDPE surfaces modified with PEG and heparin were prolonged. The VSMC growth and adhesion on the modified surfaces were promoted. Conclusion\ PEG and heparin could be attached to LDPE surface by plasma initiation technique. The modified surfaces provide good antithrombogenicity and tissue compatibility.