Objective To examine the relationship between ratio of proliferating cell nuclear antigen (PCNA)/apoptosis and biology of hepatocellular carcinoma. Methods Thirty five cases of hepatocellular carcinoma were studied with TUNEL and immunohistochemistry. Results Positive rate of apoptosis in grade Ⅰ, Ⅱ, Ⅲand Ⅳ was 1.37%,0.70%, 0.67% and 0.25% respectively. Positive rate of PCNA in grade Ⅰ, Ⅱ, Ⅲ and Ⅳ was 17%, 19%, 75% and 80%. Ratio of PCNA/apoptosis in grade Ⅰ,Ⅱ,Ⅲ and Ⅳ was 19.04, 75.51, 138.01 and 345.52. Conclusion Ratio of PCNA/apoptosis is correlated with histological classification.