Abstract: The Maillard reaction is an important and ubiquitous reaction during food processing,storage and cooking. The end product of Maillard reaction,named as melanoidins,are brown polymers with high molecular weight compound with complex structures. Melanoidins not only endow food color and flavor quality,but also show a variety of functional activities,it has been a hot research field in food science for many years. Therefore,based on the description of the Maillard reaction process,this paper summarized the research progress of the source,preparation,separation and purification,physical and chemical properties,structural characterization and functional activity of melanoidins. Moreover,the research value of the research would be expected in order to provide reference for the related research and application development of food melanoidins.