Abstract:Betalains are natural，water-soluble plant pigments，which are beneficial to health.They are usually used in food coloring and have important application value in functional food and cosmetics.In recent years，betalains in red beet（Beta vulgaris L.），dragon fruit（Hylocereus undulatus Britt.），and other plants have been studied，and some achievements have been made.In this paper，the basic structure，physiological function，extraction process，stability，color protection method，and application of betalains in the fields of medicine and food were reviewed，and their prospects were proposed，which would provide reference for betalain research in the future.