Abstract: Objective:To investigate the effects of microvascular invasion(MVI) on the prognosis of hepatocellular carcinoma (HCC) after liver transplantation.Methods:The clinical data of 183 HCC patients treated with orthotopic liver transplantation were retrospectively analyzed.Seventy-six cases according with the Milan standard,84 cases according with USCF standard,102 cases according with Shanghai standard and 126 cases according with Hangzhou standard were identified.The 1-year,3-year and 5-year cumulative survival rates in four groups were calculated using Kaplan-Meier method,and the differences of survival curves among the four groups were compared using Log-Rank test.Each group was subdivided into the MVI group and non-MVI group,and the recurrence rate of tumor,5-year disease-free survival rate,and 1-year,3-year,5-year survival rates were compared between two groups.Results:There was no statistical significance in survival time among four groups(P>0.05).With the expansion of liver transplantation standard,the MVI rate gradually increased,the 3-year,5-year survival rates and 5-year disease-free survival rate gradually decreased(P<0.05).Among the patients according with Shanghai standard,the tumor recurrence rate in non-MVI group was lower than that in MVI group(P<0.05),and the 5-year survival rate and 5-year disease-free survival rate in non-MVI group were higher than that in non-MVI group(P<0.05).Among the patients according with Hangzhou standard,the tumor recurrence rate in non-MVI group was lower than that in MVI group(P<0.05),and the 5-year survival rate and 5-year disease-free survival rate in MVI group were higher than that in MVI group(P<0.05 to P<0.01).Conclusions:Microvascular invasion can predict the recurrence of HCC after liver transplantation,which has guiding significance in comprehensive treatment of liver transplantation.