Abstract： Objecfive To investigate multi-slice spiral CT(MSCT)appearances of pulmonary infections after liver transplantation(LT)and the diagnostic values of MSCT.Methods The clinical data and CT images of liver transplantation receptors were reviewed from 200 1 August to 2007 June,the types,onset time and CT appearances of pulmonary infections were analyzed retrospectively.Chi square test was used for the statistics.Results The incidence rate of pulmonary infections after LT was 32.9/(174/529),the mortality was 9.8/(1 7/174),The incidence of bacterial infection,fungus or associated fungus infection,and virus or associated virus infection were 17.2/(n=91),14.7/(n=78)and 2.3/(n=12)respectively,the pulmonary infections were seen in 64.7/,28.7/and 6.6/of patients 1 to 30 days,31-90 days and after 90 days following LT.Consolidations(n=32),ground-glass opacities(n=22),nodules(n=10),reticular or lineal opacities(n=4)were found in 45 patients who had CT examination,there were no statistic differences in incidence rate between bacterial infection and mycotic infection(P＞0.05).Conclusion Pulmonary bacterial and fungus infection are common after LT.and often present as the mixed infection,the high risk period for infection is within 30 days after LT,thoracic CT stall is very important for characterizing the pulmonary infections after LT.