Objective The usefulness of measurement of nuclear DNA content elevation for diagnosis of early hepatocellular carcinoma was evaluated by a study of 186 patients with liver cirrhosis. Methods Nuclear DNA content was measured using an automatic image analysis system.Results ①Hepatocellular carcinoma was found in 37 patients during 10 years follow-up, the cumulative incidence of hepatocellular carcinoma was 19.89%. ②The incidence of hepatocellular carcinoma increased with the increase of the patterns of α-fetoprotein (AFP), 5c exceeding rate (5cER), FORM PE, but positive predictive value of 5cER was the highest of three parameters, the difference among all groups was significant by the χ2 test (Ｐ＜0.05). ③When 5cER joined AFP for monitoring development of hepatocellular carcinoma, the incidence of hepatocellular carcinoma was 72.00%, which was significantly higher than that of 5cER or AFP alone, the difference between groups was highly significant (Ｐ＜0.01). Conclusion Patients who had 5cER levels of 3%-5% or more, who had transient increases in 5cER or who had both, should be treated as being in a super-highrisk group for hepatocellular carcinoma. Frequent and careful examination by ultrasonography of such patients is recommended. It is important that measurement of 5cER join with AFP in cirrhotic patients monitored for early development of hepatocellular carcinoma.