Abstract: In order to improve the anti-digestibility of rice starch，the change law of digestibility and multi-scale structures of the fermented rice starch-proanthocyanidins complex，including the particle morphology，lamellar structure，crystalline structure，helical structure and short-range ordered structure，were systematically studied with modern analytical techniques and the method of fermentation and interaction with proanthocyanidins.Meanwhile，the molecular mechanism of rice starch anti-digestibility controlling by fermentation and combination with proanthocyanidins was revealed.The results indicates that the rapidly digestible starch and slow digestible starch contents of the fermented rice starch after interacting with proanthocyanidins are decreased，whereas the resistant starch contents are significantly increased.Moreover，the interaction between proanthocyanidins and fermented rice starch can promote the formation of specific ordered structure.And partial proanthocyanidins in the amorphous region can be released to inhibit the action of amylase during the digestion process，which synergisticly reduces the digestibility of fermented rice starch.The results provides foundations for improving the nutritional functions of fermented rice products.

Key words: starch, fermentation, proanthocyanidin, starch digestibility, structure change