Aim To investigate the relationship between serum total bilirubin level and the major adverse cardiovascular events (MACE) in peri operation period undergoing percutaneous coronary intervention (PCI) in patients with unstable angina pectoris. Methods Analyse 1113 unstable angina pectoris patients underwent PCI from January 2012 to March 2015, statisticiy summarize the serum total bilirubin and other biochemical parameters, obtain the data of clinical characteristics and PCI, record the occurrence of MACE in peri operation period. Patients were divided into MACE group and non MACE group. Results Serum total bilirubin level in MACE group obviously decreased than that in the non MACE group, the difference was statistically significant (P＜0.05), the application of COX regression multivariate analysis showed that increase of serum total bilirubin was an independent protective factor of MACE in peri operation period undergoing PCI in unstable angina pectoris patients (RR＝0.7,5%CI was 0.867～0.970, P＜0.01). Conclusion High serum total bilirubin is an independent protective factor of MACE in peri operation period undergoing PCI in unstable angina pectoris patients.