Abstract: Objective: To investigate the clinicopathology significance of mouse double minute 2(MDM2) expression in hepatocellular cancer tissue.Methods: The expressions of MDM2 in 172 cases hepatocellular cancer tissues were detected using immunohistochemistry.The relationship between MDM2 expression and clinicopathology,and clinical data were analyzed.The survival of patients was tested using log-rank,and the prognosis of patients was analyzed using Cox proportional hazards model.The MDM2 protein expression in HepG2 hepatocarcinoma cells was silenced,the effect of which on the proliferation and colony formation of HepG2 cells were observed.Results: The positive rate of MDM2 in liver cancer patients was 53.2%.The high MDM2 expression was related to lymph node metastasis,tumor grade and microvascular invasion(P<0.05 to P<0.01),and the high MDM2 expression was not significantly associated with the gender,age and hepatitis B status of patient,tumor size,membrane integrity,whether multiple tumor,BCLC staging and tumor recurrence(P>0.05).The univariate analysis showed that the high MDM2 expression was related to the poor survival rate(P<0.05 to P<0.01),and the Cox proportional hazards model analysis showed the effect of high MDM2 expression in predicting the prognosis of patients with was poor hepatocellular cancer(P<0.01).The siRNA silencing the MDM2 expression in HepG2 hepatocellular cancer cells could inhibit the proliferation and colony formation of cells.Conclusions: The high MDM2 expression in patients with liver cancer is associated with tumor progression,MDM2 may be associated with the poor prognosis of patients.