Abstract: Rare sugars are a kind of prebiotics with special chemical structure and bioactivities such as regulate intestinal flora, inhibit pathogen, resist oxidation, improve immunity, antitumor and so on. Rare sugars were widely used in the production of health food, infant formula food, dairy products as well as functional drinks. Nowadays, series progress has been made in the discovering of novel rare sugar, structural analysis, optimization of producing process, enzyme engineering, metabolic engineering and Izumoring strategy research. This paper reviews and prospects above advances, focuses on the research progress of bioactivity and biotransformation of rare sugars, and discusses their industrial application potential, existing problems and solutions, to provide a theoretical basis for the development, function mining and industrial production and utilization of rare sugars.