the hepatic artery was embolized with absolute ethanol in 13 mongrel dogs to evalutate the embolic effect and safety of this material. Follow up angiography and liver function test were performed at 15minutes, 1week and 4weeks after embolization. Retrograde cholangiography, microangiography and pathologic examination were done at 4weeks after embolization. The result was as follows : 1. Sequential angiography showed successful and persistent occlusion of intrahipatic arteries at different levels, and reconstitution of the intrahepatic arterial circulation via collaterals. 2. Microangiography revealed avascular area in 5 cases. but in incompletely infarcted area there showed tortuous hepatic arteries. decreased perfusion of sinusioid and microcollaterals through the interlobular arteries, capsular arteries and peribiliary vascular plexus. In one case sparse peribiliary plexus was observed. 3. Rerograde cholangiography revealed findings of cholangitis on involved segment. 4. The absolute ethanol was effective for achieving a permanent occlusion of intrahepatic arteries but caused damage on sinusoid and hepatic parenchyme, and on peribiliary vascular plexus resulting in sclerosing cholangitis. So in further clinical application, caution would be necessary to superselect the tumor supplying artery to avoid unnecessary parenchymal damage.