Abstract: Both starch and dietary fiber, which are important nutrients in cereals, and are beneficial to human health. The digestion rate and digestibility of starch are key factors affecting postprandial blood glucose in the human body. Dietary fiber, that is a nutrient content, has been not easily digested by small intestine, and has the effect of slowing down the digestion of starch, has received much attention in recent years. In this study, the effects of dietary fiber on starch digestibility have been reviewed, and the mechanisms of dietary fiber slowing down starch digestibility from three aspects: reducing amylolysis kinetics, delaying gastric emptying by viscosity of dietary fiber, physical embedding of starch by dietary fiber and wrapping starch with intact cell wall have been summarized, so as to provide a theoretical basis for the subsequent design and production of low glycemic index (GI) foods.