To assess the relationship between C-erbB-2, p53, N-ras slams at a premalignant stage and in HCC, the authors studied the imunohistological expression of these genes in IlCC, liver cirrhosis and in the adjacent normal resected liver tissue, using monoclonal antibody to mutated p53 and activated C-erbB-2, N-ras. C-erbB-2 was expressed in 97.1% (35136) of HCC and 100% (18118) of hepatic cirrhosis, low level C-erbB-2 expression was observed in 2/14 (14.3%) of normal liver specimens; The positive incidence of overexpression of mutant p53 protein in HCC and hepatic cirrhosis were 55.6% (20/36) and 66.7% (10/18) respectively; 29 (76.5%) specimens of HCC and 16 (88.9%) of hepatic cirrhosis were positive for N-ras protein. The overexpression of the three oncogene proteins were significantly higher than that of normal liver tissues (P<0.01). These results indicated that activated C-erbB-2, N-ras and altered p53 genes may have a role in human HCC pathogenesis through promiting the development of HCC from hepatic cirrhosis and the progression of HCC.