Objective: To estimate the therapeutic effect of intra-aortic balloon pump(IABP)on serious patients undergoing coronary artery bypass grafting. Methods:IAB catheters were inserted in the bodies of 31 serious patients undergoing coronary artery bypass grafting(LVEF≤40%) before operation and IABP worked after heart rebeating. Diastolic blood pressure,cardiac output,urine volume and dose of cardiovascular drugs were recorded before use and stopping of IABP. Results:Only one patient undergoing coronary artery bypass grafting died because of right heart insufficiency,and the total mortality was 3.2%.The other patients stayed in ICU for two to eight days. Diastolic blood pressure,cardiac output,urine volume before use of IABP were significantly lower than those before stopping of IABP. Dose of cardiovascular drugs before use of IABP was significantly higher than that before stopping of IABP. Conclusion:Application of IABP in the serious patients undergoing coronary artery bypass grafting can obstain good circulation support and elevate ratio of operation achievement.