Abstract: Objective: To observe the effect of Berchemia kulingensis ( BK) polysaccharide on immune function and antioxidant activities in aged mice. Methods: Carbon clearance index, thymus index, spleen index, serum immune globulin, superoxide dismutase ( SOD) , glutathione peroxidase ( GSH- Px) and malondialdehyde ( MDA) in serum and liver were observed in aged mice. Results: BK polysaccharide could enhance carbon clearance index and phagocytosis index, increase spleen index and thymus index, enhance the content of immunoglobulin G ( IgG) and immunoglobulin M ( IgM) in serum, improve the activities of SOD and GSH- Px in serum and liver, decrease the content of MDA in serum and liver. Conclusion: BK polysaccharide could improve the immune function and antioxidant activities in aged mice.