CT was investigated in 125 cases of hepatocelluar carcinoma and 47 cases of metastatic hepatic neoplasm. The entire contour of each tumor was traced and the average CT value in the tumor was estimated. As a result, the CT value for hepatocellular carcinoma tended to be higher on plain CT and also after contrast enhancement. The CT findings seen frequently were as follows: capsule in 76 cases (60.8%) and septum in 67 cases (53.6%); tumor thrombus in portal vein in 39 cases (31.2%) and that in inferior vena cava in 3 cases (2.4%); localized enlargement of hepatic bile duct in 24 cases (19.2%). These findings were rarely seen in the cases of metastatic hepatic neoplasm. As a relatively outstanding feature of hepatic metastases, a double contour, like concentric circles or contour lines, with a relatively large inner circle or contour line, was found in 21 cases (44.7%). By paying attention to the change of CT value on contrast enhancement and the characteristic image of each case, hepatocellular carcinoma could be differentiated from metastatic hepatic neoplasm with high probability.