To investigate the reasons why primary liver cancer (hepatocellular carcinoma, HCC) is prevalent in male, androgen receptors (AR) in cytoplasm and nucleus were quantitatively detected in tumor tissue and tumor-adjacent tissue of 23 patients with HCC and liver tissue of normal livers by means of receptor radio-ligand binding assay. The concentrations of AR in cytoplasm and nucleus were as follows: 0.20-5.30, 1.91-6.50 fmol/mg protein in normal liver tissue; 5.12-27.62, 10.73-47.18 fmol/mg protein in tumor tissue; and 3.18-14.98, 5.15-36.32 fmol/mg protein in tumor-surrounding tissue. The mean concentrations of AR in cytoplasm or nucleus decreased in the order of tumor tissue, tumor-surrounding tissue and normal liver tissue, and the differences among them were statistically significant. The concentration of AR in tumor tissue and tumor-adjacent tissue had no direct or indirect association with sex, age, abuse of alcohol, HBsAg, HBcAb, AFP, pathological type of tumor, differentiation degree of tumor cells and the underlying liver disease. The result suggests that the prevalence of HCC in male over in female in China may be somehow related to the expression of AR in tumor cells.