The mediative effect of yeast polysaccgaride on the intestinal microflora of egg-laying chicks was studied. The level of polysaccharide in drinking water was 0.1% and 0.5%. The result showed that the quantity of XE.coli and Salmonella in the intestine of chicks decreased in trial groups (P<0.01) and the lactobacillus increased in somewhat. The average gain of trial groups was higher than that of control group (P<0.01).