In order to study the immuno exciting function of cornel polysaccharide,50 small rats were divided into blank control group,model group,lentinan group,cornel polysaccharide group in large dose,and such group in small dose to observe its effect on celiac macrophage phagocytic function,hemolysin and hemolytic plaque formation,and lymphocyte transformation in immunsuppressant rats induced by CY.It is indicated that there is a higher content of polysaccharide in cornel with good immuno exciting function.