Many clinical studies demonstrate that complete revascularization with total arterial grafts leads to the best late surgical results. Though off-pump coronary artery bypass grafting (CABG) is superior to on-pump CABG (ONCABG) in morbidity and mortality, some coronary surgeons feel it difficult to revascularise multi-vessel disease completely without cardiopulmonary bypass (CPB). Acute conversion from off-pump to on-pump results in increased major complications and high mortality. For the patients with high risk for CPB, coronary revascularization should be performed without CPB even if completeness is failed. It seems to be reasonable to adopt ONCABG for low risk patients who need many anastomoses in the posterior wall of the heart.