Objective:To research the immune activities of Rosa laevigata michx polysaccharide（RP）.Methods:After feeding mouse with RP for several days to determine:1.Mouse MΦ’S ability of removing Congo Red from the blood.2.RP’s effect on haemolysin content in mouse body induced by chicken erythrocytes.3.RP’s effect on the delayed-type hypersensitivity（DTH）induced by 2

4-dinitrofluorobenzene.4.RP’s immune modulation effect on mouse liver immune injure induced by BCG and LPS.Results:1.RP（125mg-250mg/kg）has strong ability to enhance mouse M  to swallow Congo Red.Compared with normal control group

it could significantly reduce the content of Congo Red in mouse blood （p<0.001）.2.RP can significantly enhance the content of haemolysin in mouse body.3.RP can significantly enhance response of the DTH in normal mouse and recover response to DTH in cyclophosphamide（Cy）intoxicated mouse.4.RP has obvious immune modulation effect on mouse liver immune injure induced by BCG and LPS.

and reduce the content of ALT and AST in serum（p<0.01 and 0.001）.Besides

they all can reduce the liver and spleen index.Conclusion:RP can enhance the immune reaction in mouse and has immune modulation function.