Properties of Various Fatty Acid Methyl Esters Tested for Effects on Oxidation: Compared to conventional diesel fuel, biodiesel fuel consisting of fatty acid methyl ester has an oxidation problem which deteriorates the stability of the fuel properties and causes fuel storage issues. In an effort to find ways to prevent oxidation of biodiesel fuel, researchers at Shiga Prefecture University continue their study and evaluated oleic acid methyl ester, linoleic acid methyl ester, and linolenic acid methyl ester through thermal oxidation processes with a Racimate tester under various temperature and aeration conditions. The tests were conducted excluding the effect of antioxidants. The chapter consists of 10 pages including 9 figures.