We developed new embolic drug delivery emulsions to be utilized for malignant neoplasms. We combined additional water-soluble contrast materials (Ioxaglic acid, Iopamidol) with Glyceol, Poloxamer-188, or D-Mannitol to antitumor agent Lipiodol ultrafluid in order to generate stable emulsions. Some of these emulsions have been shown to cause pulmonary embolism in rabbits and to allow gradual diffusion of the antitumor agent in vitro. Good therapeutic utility is indicated. In particular, one emulsion containing D-Mannitol (Mizonokuchi emulsion), is expected to prolong drug delivery in malignant brain tumors.