Abstract: OBJECTIVE To explore the influencing factors for postoperative pulmonary infection in the cardiac valve replacement patients and observe the changes of myocardial enzymes. METHODS A total of 517 patients who received cardiac valve replacement in Tangshan Gongren Hospital from Mar 2013 to Jan 2018 were enrolled in the study, the incidence of postoperative pulmonary infection and etiological characteristics were observed, and the related factors for the pulmonary infection and myocardial enzymes were compared. RESULTS Of the 517 cardiac valve replacement patients, 68 (13.15%) had postoperative pulmonary infection. Totally 79 strains of pathogens were isolated, 47 (59.49%) of which were gram-negative bacteria, 22 (27.85%) were gran-positive bacteria, and 10 (12.66%) were fungi. There were significant differences in left ventricular ejection fraction (LVEF), duration of use of ventilator, incidence of sternal duodenum, incidence of low cardiac output syndrome and rate of reoperation for hemostasis between the infection group and the non-infection group (P<0.05). The univariate analysis and multivariate logistic regression analysis showed that smoking history and complication with underlying diseases were the independent risk factors for the postoperative pulmonary infection in the cardiac valve replacement patients (P<0.05). The levels of myocardial enzymes of the infection group were significantly higher than those of the non-infection group (P<0.05). CONCLUSION The incidence rate of postoperative pulmonary infection is high among the cardiac valve replacement patients. The gram-negative bacteria are dominant among the pathogens. Smoking history and complication with underlying disease are the independent risk factors for the postoperative pulmonary infection. The postoperative pulmonary infection may result in the decrease of myocardial function.