Purpose : To evaluate the usefulness of new liquid embolic materials for portal vein embolization (PVE).Materials and Methods : The liquid embolic material, Embol, was obtained by hydrolytic reaction of polyvinylacetate (PVAc). Several Embols with a different hydrolysis ratio and polymer concentration were prepared andnamed, an example was Embol-78-12. These were percutaneously injected through a 5-Fr catheter into the left portalvein of six pigs, and radio-opacity under X-ray fluoroscopy and the possibility of reflux were evaluated. Results: The radio-opacity of Embol-78-8, Embol-73-10, and Embol-73-12 was too low to recognize reflux, but was excellentwhen Embol-78-12 or (Embol-78-12 + Lipiodol) was used; it was still difficult to prevent reflux, however. With theuse of a balloon catheter, however, complete embolization became possible. Conclusion : Embol-78-12 injectionthrough a balloon catheter seems to be useful for clinical PVE.