PURPOSE: To evaluate ethanolamine oleate (EAO)-microfibrillar collagen (MFC) mixture as a new scleroembolic material for the interventions requiring both permanent obliteration of vascular lumen and atrophy of mass, such as for the facial AVM and other hypervascular soft tissue masses. MATERIALS AND METHODS: Twenty-nine transcatheter transarterial embolizations of renal arteries were performed in six groups of rabbits classified by the EAO concentration and the addition of MFC. Postembolization angiography, gross morphological and microscopic examinations of embolized kidneys were performed immediately, 3 days, 2 weeks and 4 weeks after embotization. Analysing points were the usefulness as a scleroembolic material (endovascular retention, thrombogenic-sclerosing effect, perivascular fibrosis and inflammatory reaction), effects of the EAO concentration and the addition of MFC. RESULTS: EAO-MFC mixture satisfied all ideal conditions of scleroembolic agent;persistent endovascular retention, good thrombogenic-sclerosing effect with a mild inflammatory reaction and significant atrophy of kidney. The effect of increasing concentration of EAO was proximal embolization. The effects of MFC were promotion of proximal embolization, endovascular retention and sclerosing effect. CONCLUSION: EAO-MFC mixture can be used as a new effective scleroembolic material for the various hemodynamic situations in which embolic level can be controlled by EAO concentration and the addition of MFC.