Purpose To explore the relationship between the change of space anterior to right portal vein and the pathological staging in liver ifbrosis/cirrhosis. Materials and Methods Plain and contrast enhanced CT scan were performed in patients with biopsy proven liver ifbrosis/cirrhosis including S1 in 17 patients, S2 in 13 patients, S3 in 15 patients, S4 in 21 patients and cirrhosis in 22 patients. Twenty subjects were included as control group. The width of anterior space of right portal vein was measured on contrast enhanced CT and correlated with ifbrosis staging. The receiver operating characteristic curve was created for cirrhosis diagnosis. Results The width of anterior space of right portal vein enlarged in patients with S3 ifbrosis to cirrhosis (P<0.05 or P<0.01). It was signiifcantly bigger in group S4 compared to other groups (P<0.01). Spearman rank correlation analysis showed significant positive correlation between the width of anterior space and liver fibrosis staging (r=0.704, P<0.01). ROC curve analysis showed the area under curve (AUC) of 0.897 with the optimum width of ≥10 mm. Conclusion The change in the space anterior to the right portal vein is positively correlated with live ifbrosis staging. CT measurement helps early diagnose and assess the severity of liver ifbrosis and cirrhosis.