Purpose: To evaluate the anatomy of the hepatic artery and normal variants using oblique thick-slab maximal intensity projection (MIP) 3-D CT angiography and multidetector helical CT technology. Materials and Methods: In 70 patients, axial three-phase CT together with multidetector helical CT and a nonionic contrast agent was used to evaluate liver disease. During the early arterial phase, the parameters were as follow: ice thickness,2.5 mm; table speed, 15 mm/rotation, pitch,6; contrast material,4 ml/sec; total 120 ml. Using the MIP technique and an Advantage window voxtal 3.03 system (GE), the images obtained were reconstructed as 3D angiograms. In each case, the arterial anatomy and its variants were recorded. Results: A typical anatomy was found in 53 cases (75.7%). Common variants were a left hepatic artery arising from the left gastric arteryfB cases, 11.4 %1 and a right hepatic artery arising from the superior mesenteric artery(3 cases,4.37o). Other variant cases were a right hepatic artery arising from the gastroduodenal artery(2 cases, 2.97o), a proper hepatic artery arising from the left gastric arterr (l case, 1.4%), a hepatomesenteric trunk (l case), a hepatogastric/splenomesenteric trunk(1 case), and a celiomesenteric trunk fl case). Conclusion: 3-D hepatic angiography using multidetector helical CT technology is non-invasive and as accurate as conventional angiography for the evaluation of hepatic arterial anatomy. It is thus considered that 3-D CT angiography is very helpful for the evaluation of hepatic arterial anatomy prior to liver surgery such as transplantation or the treatment of hepatocellular carcinoma.