Objective To explore the correlation between liver volume variation of posthepatitic cirrhosis patients and the severity of the disease. Methods One hundred and eleven patients with normal livers and 74 posthepatitic cirrhosis patients underwent volume CT scan. The relation between normal liver volume and body height, body weight and body surface area was studied by linear regression and correlation method, the standard liver volume equation was deduced. The change ratio of liver volume in cirrhotic patients was calculated and compared with Child classification. Results The mean normal liver volume of Chinese adults was （1 225.15±216.23） cm3, there was a positive correlation between liver volume and body height, body weight 〔liver volume (cm3)=12.712×body weight (kg)+450.44〕 and body surface area 〔liver volume (cm3)=876.02×body surface area (m2)-297.17〕. The mean liver volume of Child A, B and C patients were （1 077.77±347.01） cm3, (1 016.35±348.60) cm3 and (805.73±208.85) cm3 respectively. The liver volume and liver volume index was significantly smaller in Child C patients than those in Child A and B patients (P＜0.05); while liver volume change ratio was higher in Child C patients (P＜0.05). Conclusion Liver volume variation of cirrhotic patients can be quantitatively assessed by 16 slices helical CT volume measurement and standard liver volume equation. The change of the liver volume is correlated with the severity of liver cirrhosis.