Abstract: In order to lay a theoretical foundation for production and quality control of sourdough,changes in degradation of glutenin macropolymers in sourdough fermentation were investigated in this study.Sourdough was prepared using wheat flour,water and Lactobacillus plantarum M616 and changes of glutenin macropolymers in sourdough fermentation were analyzed.The results indicated that GMP content in SL,SYL and SA samples decreased compared with untreated (control) dough in the fermentation process.The contents of amino nitrogen (AN) and soluble nitrogen (SN) increased drastically in sourdoughs at the beginning,and with extended fermentation time,the increase trend slowed down.The content of peptide nitrogen (PN) increased at the initial stage of fermentation and decreased at later period of fermentation.The results also demonstrated that sourdough fermentation resulted in increased free sulfhydryl group but decreased disulfide bond of GMP.These phenomena indicated that degradation or depolymerization of GMP occurred in sourdough fermentation process.