Assessment of liver blood flow through transcutaneous duplex Doppler sonography could be a very important method for detection of clinically relevant changes in hepatic perfusion specially in liver cirrhosis and hepatocellular carcinoma. Occurrence of hepatocellular carcinoma , hypervascular tumor further increases the hepatic arterial blood flow with increase in hepatic perfusion index which is calculated as the ratio of hepatic arterial blood flow to total hepatic blood flow. This index could be regarded a reflection of progression in chronic hepatic diseases. Our study was conducted on 30 patients with liver cirrhosis, 30 with hepatocellular carcinoma and 30 controls. All patients subjected to through examination, routine laboratory tests, abdominal ultrasound and transcutaneous duplex Doppler sonography. We found that the patients with liver cirrhosis had significant increase of hepatic blood flow and so Doppler perfusion index as compared to controls. Hepatic blood flow was increased in hepatocellular carcinoma patients and so Doppler perfusion index as compared to liver cirrhosis patients and controls. These results suggest that hepatic arterial buffer response seems to be active in hepatocellular carcinoma to maintain liver perfusion.