Abstract: The aggregates of four kinds of soy protein from different production processes were formed with the different morphologies at low pH and heating at 90℃ for 10h. Thioflavin T (Th T) fluorescence, differential scanning calorimeter (DSC) , and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to monitor the kinetics of aggregation and the protein compositions. The results indicated that protein compositions were remarkably different due to the different production processes. The glycinin (11S) , especially basic subunits inhibited the formation of fibril aggregates under the test condition. In addition, ionic strength played an important role in the formation of fibril aggregates.