Abstract: Protein thermal aggregation behavior is a frequent phenomenon in the food processing. The heat treatment conditions could change the structure of proteins,causing changes in the physical and chemical properties of the protein,which lead to the thermal aggregation of protein. The size,shape and interface of the thermal aggregates directly affect the protein gel property,solubility,foaming property,emulsifying property and other functional characteristics,which influences the quality of protein-rich foods. In this paper,the mechanism,classification and characterization of protein thermal aggregation were presented. The influencing factors and the effect of protein thermal aggregation on protein function were reviewed. The study would provide a theoretical basis for the thermal aggregation behavior of complex protein system and its effect on food quality.