Objective To evaluate the effect of Levosimendan on the prognosis in patients with severe coronary heart disease after operation. Methods A total of 485 severe coronary disease patients undergoing coronary artery bypass grafting from Teda International Cardiovascular Hospital and the Cardiac Surgery Department of the First Affiliated Hospital of China Medical University from May 2014 to June 2016 were enrolled.Of them, 45 cases receiving Levosimendan postoperatively were assigned to the Levosimendan group, and according to propensity score matching, another 45 cases were selected as the control group in this study.Clinical data before treatment had no difference between the groups(P>0.1). Postoperative prognosis was compared between the two groups. Results There were significant differences in heart rate, mean arterial pressure, central venous pressure, cardiac output and other hemodynamic parameters between the two groups 48h after operation.The heart ultrasound results showed that the left ventricular ejection fraction(LVEF)was increased[(0.53±0.12)%vs.(0.46±0.09)%, t=2.594, P=0.002], the postoperative ventilation time was reduced[(46.8±11.3) h vs.(58.5±16.3) h, t=-2.031, P=0.045]and the onset of bowel sounds became early[(16.5±5.9) h vs.(18.7±10.1) h, t=1.592, P=0.039]in the levosimendan group than in the control group 48h after operation.The incidences of new-onset acute kidney injury(20% and 40%, χ2=6.702, P=0.018), new-onset postoperative atrial fibrillation(15.6% and 44.4%, χ2=6.156, P=0.023)and perioperative myocardial infarction(11.1% and 33.3%, χ2=6.429, P=0.021)had significant differences between the two groups(P 0.05). Conclusions Levosimendan can improve the early prognosis of severe coronary disease patients undergoing coronary artery bypass grafting and reduce the occurrence of postoperative organ dysfunction. Key words: Levosimendan; Coronary artery bypass, off-pump