Abstract: Taking Poria cocos polysaccharide as the research object,the digestion and absorption process of Poria cocos polysaccharide in rats was studied by simulating human gastrointestinal environment in vitro and intestinal perfusion in vivo. In this experiment,the degradation of Poria cocos polysaccharide in artificial gastric juice was detected,then the degradation of gastric degradation fluid in artificial intestinal juice was detected,and finally the absorption of polysaccharide in body intestine was explored. The results showed that Poria cocos polysaccharide was degraded rapidly and completely in artificial gastric juice within 0.5 h,forming many fragments stable in gastric juice,and almost no degradation in intestinal juice. Poria cocos polysaccharide were mainly absorbed in the intestine,and the higher the initial concentration of polysaccharide,the higher the absorption percentage(ρ). In the process of absorption,the absorption rate constant(Ka)of different initial concentrations of polysaccharides increased at first and then decreased. When absorbed to 120 min,the absorption percentage of the gastrointestinal degradation solution with initial polysaccharide concentration of 0.1004,0.5007 and 1.0004 mg/mL reached(23.52%±0.57%),(49.14%±0.87%)and(57.56%±0.22%),respectively. The study showed that Poria cocos polysaccharide were mainly degraded in gastric juice and absorbed in body intestine in mice.