Objective To analyze the value of modified caudateright lobe with use of the right portal vein to set the lateral boundary in CT diagnosis of viral hepatitis cirrhosis and its correlation with Child-Pugh grading of liver cirrhosis. Methods One hundred patients with viral hepatitis cirrhosis, including 30 cases of Child Pugh A, 36 cases of Child Pugh B and 34 cases of Child Pugh C, and 100 normal controls were performed CT scan. Plain and enhanced CT images of 200 patients were retrospectively analyzed. Three experienced physicians measured C/RLr and compared the differences between the two groups and that of three Child Pugh staging groups. Results The C/R-r for the patients with cirrhosis of liver were higher than the control group (P＜0.05). A difference in C/RL-r was found between the three Child Pugh staging groups (P﹤0.05). The C/RLr for Child B patients was higher than that of Child A and Child C patients(P﹤0.05, P﹤0.05). The C/RL-r for Child C patients was higher than that of Child A (P＜0.05).Conclusion Modified caudate-right lobe ratio may has significant value for the CT diagnosis of viral hepatitis cirrhosis, but has no positive correlation with liver function ChildPugh classification.