Abstract: To investigate the effect of Collybia radiata polysaccharide on intestinal flora and secretory immunoglobulin A ( SIg A) of mouse, the detection of intestinal flora and SIg A were carried out on the mice kunming mice.Lincomycin hydrochloride intragastric administration was used to construct mouse intestinal dysbacteriosis model.Sixty mice were randomly put into one standard control group, one spontaneous recovery group and three different doses of Col ybia radiata polysaccharide treatment groups, fed polysaccharide at dosage of 75, 150 mg / kg·bw, and 300 mg / kg·bw, respectively. After being treated for 14 days, the counts of Bifidobacterium, Lactobacillus, Escherichia coli, Enterococcus and SIg A were assayed. The results showed that compared with the standard control group, intestinal microflora was disturbed and the content of intestinal mucosal SIg A was significantly decreased in the other four groups. And compared with the spontaneous recovery group, the above indexes renewed to some extent.The results indicated that Collybia radiata polysaccharide has played a role in adjusting intestinal flora and improving content of SIg A.