PURPOSE: As one of non-invasive methods evaluating disorders of renal perfusion using Doppler ultrasonography, PI represents the characteristics of Doppler waveform more accurately than RI, and even when renal perfusion is severely impaired, objective estimation is possible because of using the mean velocity in its calculation. The purpose of this study is to find out the clinical usefulness of PI for evaluating disorder of renal function in patients with liver cirrhosis. MATERIALS AND METHODS: The subjects were 167 patients including 89 of Child A and B groups, 39 of Child C group, and 39 of control group. We compared PI, RI, creatinine clearance, serum renin activity and aldosterone level between each groups, and investigated the relationships of PI with creatinine clearance, serum renin activity, and aldosterone level. RESULTS: Mean PI was 1.00+/-0.15 in control group, 1.17+/-0.22 in Child A and B groups, and 1.30+/-0.28 in Child C group, which showed significant difference between each groups(p<0.05). Also RI, creatinine clearance, serum renin activity and aldosterone level revealed significant difference between each groups(p< 0.05). PI showed significant negative relationships with creatinine clearance(p= 0.009), serum renin activity(p= 0.006), and aldosterone level(p= 0.001). CONCLUSION: Measurement of PI by Doppler ultrasonography is a useful non-invasive method for evaluating renal dysfunction in patients with liver cirrhosis.