AIM: The p-catenin has been recognized as a critical member of the Wnt signaling pathway and plays an important role in the generation/differentiation of many tissues. Inappropriate activation of this pathway has been implicated in carcinogenesis. The mechanism underlying the development as well as its prognosis of hepatocellular carcinoma (HCC) has remained unclear. The purpose of this study is to analyze the expression of p-catenin in HCC in relation to histological grades and viral hepatitis backgrounds. METHODS: Thirty-two sections were selected at random from autopsy and surgical cases of HCC. Immuohistologically, the location and positivity of p-catenin expression in HCC was examined. RESULTS: Normal hepatocytes did not express p-catenin. In 78% of HCC p-catenin was expressed at the membrane of the cells, with or without cytoplasmic and/or nuclear expression. The tumor cells with well- and moderately-differentiated grades expressed frequently at the membrane and cytoplasm compared with poorly-differentiated type. Nuclear expression of p-catenin was prone to occur in the tumor cells of poorly-differentiated grade. There were 15% of hepatitis C virus (HCV) backgrounds with nuclear expression. In contrast, there was 38% with nuclear expression in hepatitis B virus (HBV) backgrounds. In nonB-nonC hepatitis, no case expressed nuclear p-catenin. CONCLUSION: The β-catenin expression in HCC cells was heterogenous among types of hepatitis viral infection. Wnt signaling pathway might be deeply involved in less-differentiated HCC and HBV background. AIM: The p-catenin has been recognized as a critical member of the Wnt signaling pathway and plays an important role in the generation / differentiation of many tissues. Inappropriate activation of this pathway has been implicated in carcinogenesis. The mechanism underlying the development as well as its prognosis of hepatocellular carcinoma (HCC) has been unclear. The purpose of this study is to analyze the expression of p-catenin in HCC in relation to histological grades and viral hepatitis backgrounds. METHODS: Thirty-two sections were selected at random from In 78% of HCC p-catenin was expressed at the membrane of the cells , with or without cytoplasmic and / or nuclear expression. The tumor cells with well- and moderately-differentiated grades expressed frequently at the membrane and cytoplasm compare There were 15% of hepatitis C virus (HCV) backgrounds with nuclear expression. In contrast, there was 38% with non-nuclear expressed in hepatitis B virus (HBV) backgrounds. In nonB-nonC hepatitis, no case expressed nuclear p-catenin. CONCLUSION: The β-catenin expression in HCC cells was heterogenous among types of hepatitis viral infection. deeply involved in less-differentiated HCC and HBV background.