Abstract: Objective To explore the effect of perioperative oral administration of betaloc on cardiac function indexes after coronary artery bypass grafting(CABG)and evaluate its effect on myocardial protection. Methods A total of 86 patients with coronary heart disease undergoing CABG were divided into group A and group B. Thirty-eight patients in group A were orally administrated betaloc at least for more than a week before surgery, and maintained until the day of surgery, oral administration of betaloc after tracheal tube extubation, and another 48 patients in group B were not given perioperative oral administration of betaloc. Cardiac function indexes such as brain natriuretic peptide(BNP), creatine kinase isoenzyme(CK-MB)and cardiac troponin I(cTnI)were observed in the two groups after surgery, and the effect of perioperative oral administration of betaloc in improvement of cardiac function after CABG was evaluated. Results The levels of BNP, CK-MB and cTnI in the group A were significantly lower than those in group B(P<0.05). There were no serious complications in both groups during hospitalization. Conclusion Perioperative oral administration of betaloc can significantly improve cardiac function in patients after coronary artery bypass grafting.