Abstract: Objective To compare the therapeutic effects between offpump coronary artery bypass grafting (off-pump CABG) and onpump coronary artery bypass grafting (on-pump CABG) in the patients of multivessel coronary disease below 70 years old, in order to decide on the best surgery method. Methods From June 2007 to June 2009, 196 patients below the age of 70 underwent coronary artery bypass grafting (CABG), including 152 male patients and 44 female patients. The average age was 55.00 years old, ranging from 46 to 69 years. The patients were divided into two groups according to the methods of operation. There were 94 patients in the off-pump CABG group including 2 patients who were converted to the onpump CABG surgery because of the unstable hemodynamics. The other 102 patients were in the onpump CABG group. The type and number of the vessel grafts, the quantity of blood transfusion, intubation duration, length of stay in hospital, complications during perioperative period and mortality were compared between the two groups. Results In the offpump CABG group, 2 patients were converted to onpump CABG surgery because of the unstable hemodynamics, and 1 of them died from multiple organ failure. In the onpump CABG group, 2 patients died from severe low output syndrome and sudden heart arrest respectively. No significant difference was found in the vessel grafting materials, perioperative complications and mortality between the two groups (Pgt;0.05), while the number of anastomosis (3.22±0.65 vs. 4.52±1.11, t=9.807, P=0.000), the [CM(159mm]quantity of blood transfusion (312.57±305.26 ml vs. 744.86±279.37 ml, t=10.317, P=0.000),the intubation duration (10.71±5.32 h vs.17.12±4.67 h, t=8.683, P=0.000) and the length of stay in hospital (17.75±3.04 d vs. 21.24±6.46 d, t=4.782,P=0.000) in the off-pump CABG group were significantly lower or shorter than those in the on-pump CABG group. A total of 93 patients in the off-pump CABG group and 100 patients in the on-pump CABG group were followed up with the time periods ranging from 2 to 26 months. All patients survived without angina. Conclusion There is no significant difference in the early clinical therapeutic effects between off-pump CABG and onpump CABG in the patients of multivessel coronary disease below 70 years old, but revascularization in the on-pump CABG patients is better. So far, offpump CABG cannot replace on-pump CABG and more clinical trails are needed for evaluation of the longterm prognosis.