The immunophenotyping expression levels of lymphocyte in the peripheral blood from 21 patients with active systemic lupus erythematosus were analyzed by using the immunofluorescence labeling flow cytometry technique to investigate the immunophenotyping expression of lymphocytes T and B in the peripheral blood of active SLE patients and its clinical value. It was showed that, compared with normal controls, the expression of CD + 3, CD + 4 and the ratio of CD + 4/CD + 8 in the peripheral blood of these patients were decreased , while the expression of CD + 8, CD + 20 was significantly increased . It was suggested that both T and B cells in patients with active SLE involved in immunoregulation, were activated. The abnormal expression of lymphocyte immunophenotyping could influence the immune reaction in SLE patients, which might be one of the important pathogenesis factors in SLE. The immunophenotyping expression levels of lymphocytes in the peripheral blood from 21 patients with active systemic lupus erythematosus were analyzed by using the immunofluorescence labeling flow cytometry technique to investigate the immunophenotyping expression of lymphocytes T and B in the peripheral blood of active SLE patients and its clinical value It was showed that, compared with normal controls, the expression of CD + 3, CD + 4 and the ratio of CD + 4 / CD + 8 in the peripheral blood of these patients were decreased, while the expression of CD + 8, It was suggested that both T and B cells in patients with active SLE involved in immunoregulation, were activated. The abnormal expression of lymphocyte immunophenotyping could influence the immune reaction in SLE patients, which might be one of the important pathogenesis factors in SLE.