Abstract: Anthocyanidins have been extensively studied, but little is known about the important secondary metabolite betalains, a homologue of anthocyanidins in higher plants. This paper reviews the advances in betalain research: the chemical structures of identified betalains; analytical techniques concerning betalain isolation and identification; factors affecting the stability of batalains; characterization of 3 key enzymes and functional genes cloned in betalain biosynthetic pathway from some model plants; biological functions and possible medicinal properties; and the hot areas of betalain research. This information may lead to a detailed insight of betalain research.