Mice were supplemented with β-carotene and established an immunosuppression model by cyclophosphamide to study the effects of β-carotene on immune function in mice. The immune organs index,histomorphology of immune organs,cytokines and immunoglobulin in serum were detected to evaluate the role of β-carotene. The results showed that β-carotene can improve the immune organ damage caused by cyclophosphamide and the cytokine and immunoglobulin levels in serum of immunosuppression mice. It suggested that β-carotene can improve the humoral immune function, alleviate immunosuppression induced by cyclophosphamide,which lays a foundation for further study of the immune mechanism of β-carotene.