PURPOSE: To determine changes in the square index of the liver segments of liver cirrhosis(LC) patients, as seen on CT, and the value of this indicator during follow-up. MATERIALS AND METHODS: Twenty-three patients with LC were included in this study. Abdominal CT scans were performed twice in each patient and the mean follow-up period was 15 (6-36) months. We measured the square index of the right lobe, the caudate lobe, and the medial and lateral segment of the left lobe of the liver, as seen on initial and follow-up CT images, and compared the results. The square index was obtained by deter-mining the product of the transverse and longitudinal diameters. According to the Child-Pugh classification, the condition was classified as either progressive or non-progressive, and the square index was compared between the two groups. RESULTS: The square index of the left lobe medial segment showed a significant decrease in both the progression group(n=13) and non-progression group(n=10), while that of the right lobe was significantly lower only in the progression group. There was no significant change in the square index of the caudate lobe or the lateral segment of the left lobe. CONCLUSION: For predicting the progression of LC, the square index of the medial segment of the left lobe is a more sensitive index than the Child-Pugh classification. For ascertaining the progression of the condition, the square index of the right lobe is a valuable deferminant.