Objective:To explore the possibility of diagnosing and monitoring patients with systemic lupus erythematosus (SLE) using the combination of mean platelet volume (MPV) and routine immunoglobulin test. Method:116 patients with SLE were divided into 3 groups according to their clinical characteristics, including 29 patients with renal impairment, 44 cases of active stage and 43 cases of inactive patients. 40 healthy subjects were randomly selected as controls. Subjects were tested for routine blood test and plasma Immunoglobins, such as IgG, IgA, IgM, C3, C4, CH50, CRP. The results were analyzed and the characteristics of each group of subjects were determined, the correlation between test results and diagnosis were studied. Result: In comparison to the control group, the serum level of MPV,... C3 and C4 were decreased (P<0.05), and C reactive protein level was elevated (P<0.001) in the three groups of SLE patients. The IgG level in active and inactive SLE patients was increased (P<0.0001), CH50 level was decreased in patients with inactive SLE (P<0.05), IgA level of active SLE subjects was found to be elevated (P<0.05), IgM in patients with renal impairment was decreased (P<0.05). Other than that, no other significant characteristic were found. Conclusion: The pathogenesis of SLE is a complex process involving multiple factors. The changes of MPV, IgG, IgA, IgM, C3, C4, CH50 and CRP in SLE patients are characteristic parameters. The combination of the above indicators can help to determine the diagnosis and staging of SLE. The timely diagnosis and treatment of SLE patients has important clinical significance in protecting the organ function of SLE patients and improving the prognosis.