Abstract: This paper reviewed the research progress in inorganic flame retardants. Based on the classification of inorganic flame retardants which were divided into metal hydroxide, carbon-, phosphorus-, nitrogen-, silicon-and boron-containing flame retardants and the other ones, the mechanism, current research status, advantages, disadvantages and applications of each type of flame retardants were introduced extensively. Finally, the future trends in the development of inorganic flame retardants were prospected.