In order to evaluate the different effects of processing techniques on the in vitro digestion characteristics of rice products and brown rice products, steaming, boiling and extrusion techniques were used to make rice products, and their digestion characteristics, glucose diffusion and rheological property during digestion were stimulated by an in vitro oral-gastric-intestinal tract model. The results show that the glucose contents of white rice products (WRP) were 35%～50%, higher than those of brown rice products (BRP) which were about 10%～25%. The digestion rate of WRP slowed down after 30 ～45 min, while BRP could last for 90 min. The glycemic index(GI) of cooked BR, BR porridge and BR instant porridge were 76.51,83.78 and 65.49, all less than WR products (81.62,85.61 and 82.94, respectively). The porridge products performed higher glucose diffusion with more rapid rate than other type of products. The glucose diffusion rates of cooked BR and WR were 0.08g/min and 0.17g/min. The glucose diffusion of BR instant porridge stared to increase after 30min digestion, with smaller amount. In conclusion, processing techniques affect the digestion characters of rice products. Extrusion could apparently enhance the viscosity of the digestion systems, decrease the digestion and glucose diffusion rates of brown rice produces.