1. Quantitative analysis of hepatic arterial blood flow vs portal venous blood flow was performed by using computerized gamma camera named arterialization index. 2. Arterialization index was analized in normal control 10 cases and confirmed liver disease 40 cases. 3. The range of arterializaition index in normal control was 0.21-0.49. 4. Arterialization index in all cases of primary hepatoma an metastasis were over 0.6. 5. The possible condition over 0.6 A.I. except tumor invasion suggested huge liver abscess, underlying severe cirrhosis & different vascular pattern S.O.L. such as hemangioma. 6. The computerized dynamic hepatic flow study seems to be a simple noninvasive, nonexpensive diagnostic method to detect vascular change of hepatic tumor invasion. 7. The arterialization index over 0.6 will be a significant indicator of primary hepatoma or metastatic tumor invasion.