In an attempt to evaluate the specificity of monocytes in the neoplastic procsses, the change of peropheral monocyte counts were studied in the course of 47 patients with hepatocellular carcinoma. The clinical course of the patients were divided into the following six stages because of the lack of a generally accepted staging scheme for hepatocellular carcinoma : 0-9 days before the death, 10-29, 30-59, 60-89, 90-299, more than 300 days. The mean of monocyte count in each stage increased with progress of illness, but did not show statistically significant difference. The number of monocyte in peropheral blood increased in 53% of patients and decreased in 36% of patients with progress…