Abstract： Objective To evaluate prediction validation of Sino System for Coronary Operative Risk Evaluation （SinoSCORE） on in-hospital mortality in adult heart surgery patients in West China Hospital.?Methods?We included clinical records of 2 088 consecutive adult patients undergoing heart surgery in West China Hospital from January 2010 to May 2012, who were also included in Chinese Adult Cardiac Surgical Registry.We compared the difference of preoperative risk factors for the patients between Chinese Adult Cardiac Surgical Registry and West China Hospital. SinoSCORE was used to predict in-hospital mortality of each patient and to evaluate the discrimination and calibration of SinoSCORE for the patients.?Results?Among the 2 088 patients in West China Hospital, there were 168 patients （8.05%） undergoing coronary artery bypass grafting （CABG）, 1 884 patients （90.23%） undergoing heart valve surgery, and 36 patients （1.72%） undergoing other surgical procedures. There was statistical difference in the risk factors including hyperlipemia, stroke, cardiovascular surgery history, and kidney disease between the two units.The observed in-hospital mortality was 2.25% （47/2 088）. The predicted in-hospital mortality calculated by SinoSCORE was 2.35% （49/2 088） with 95% confidence interval 2.18 to 2.47. SinoSCORE was able to predict in-hospital mortality of the patients with good discrimination （Hosmer Lemeshow test: χ2=3.164, P=0.582） and calibration （area under the receiver operating characteristic curve of 0.751 with 95% confidence interval 0.719 to 0.924）. Conclusion SinoSCORE is an accurate predictor in predicting in-hospital mortality in adult heart surgery patients who are mainly from southwest China