Anthocyanin is flavonoid polyphenol, which is widely distributed in fruits, leaves, petals and seeds of plants, giving flowers and fruits a variety of colors.As a pure natural food pigment, anthocyanin can effectively scour free radicals, and enhance anti-oxidation, anti-aging and anti-inflammation.Moreover, anthocyanin may prevent obesity, chronic metabolic diseases and cardiovascular problems and improve eye vision.In recent years, research on anthocyanins is mainly in the field of plant secondary metabolism.The transport, accumulation and in vitro synthesis of anthocyanins need further investigation.This review summarizes the structure and kinds of anthocyanin, and focuses on the biosynthesis pathway and key enzymes of anthocyanin.The summarization will benefit the further exploration on the synthesis mechanism of anthocyanin in plants and its genetic improvement.