β-Aminoenones have three functional groups, i. e. amino, double bond, and carbonyl, and show the characteristic behaviors of these groups. They also behave as vinylogues of amide as well as enamine or enone. Moreovere, β-aminoenone has four geometrical isomers, trans-s-cis, trans-s-trans, cis-s-cis, and cis-s-trans. From these points of view, β-aminoenones are much interesting in synthetic, physicoorganic, biological, and pharmaceutical works. Recently, a number of papers on β-aminoenones have reported. This review containes the syntheses, reactions, and properties of β-aminoenones.