Aim To investigate the changes of microalbuminuria and to assess the role of myocardial injury after percutaneous coronary intervention(PCI). Methods 86 patients who underwent PCI were enrolled.Blood samples were respectively collected immediately before and after PCI at 24 hours,myocardial creatine kinase-MB(CK-MB),cardiac troponin I(cTnI) and myoglobin(MB) were detected by Electrochemiluminescence,then the changes of myocardial injury markers were analyzed and compared between MAU-positive group and negative group. Results After 24 hours of operating,cTnI and CK-MB levels of MAU-positive group were 1.68±0.74 μg/L and 10.16±4.18 μg/L respectively.cTnI and CK-MB levels of MAU-positive group were significantly higher than MAU-negative group(P><0.05).MB levels of MAU-positive group after 24 hours of operating were higher than preoperating(40.16±15.82 μg/L vs 16.68±6.45 μg/L),but there were no signifiant differences between MAU-positive group and MAU-negative group after 24 hours of operating. Conclusion Postoperative cTnI,CK-MB and MB levels in the two groups were higher than preoperative levels,the differences had statistical significance,it suggested that PCI caused myocardial injury;postoperative cTnI and CK-MB levels of MAU-positive group were significantly higher than MAU-negative group.Preoperative MAU being positive had significantly predicted effect on myocardial injury after coronary intervention.