Abstract: Objective: To evaluate efficacy,feasibility and safety of 32 P liquid filled balloon irradiation in preventing restenosis in swine. Methods: After overstretch balloon angioplasty injury,the left anterior descending branch（LAD） of coronary artery was treated with 32 P or control 35 days later,the morphometry and histopathologic analyses were carried out in the injured segments. Results: The lumen area was significantly larger （P＜0. 01） while the neointima area（P＜0. 01）,percent area stenosis （P＜0. 01） and PCNA positive cells （P＜0. 01） reduced sighificantly in the radiotherapeutic animals than in the control animals. Conclusion: The approach was safe,effective and feasible in preventing restenosis.