Objective:To explore the expression level of miR-203 in the peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus (SLE), and to analyze the relationship between the expression level and clinical manifestations. Methods: The PBMCs of 31 SLE patients, 16 healthy people were collected,and then SLE patients were divided into two groups, including the lupus nephritis group (21 cases) and the no kidney involvement group (10 cases). The expression level of miR-203 in PBMCs was detected by real-time fluorescence quota polymerase chain reaction (qRT-PCR). The expression levels of miR-203 in each group were compared to analyze the relationship between the expression level and clinical manifestations. Results: The expression level of miR-203 was significantly lower in the SLE group compared to the control group (P < 0.05). The expression level of miR-203 was significantly lower in the lupus nephritis group than that in the no kidney involvement group and the control group (both P < 0.01). The expression level of miR-203 was negative correlated to 24 hours urine protein, acute kidney disease index (P < 0.01). Conclusion: The expression of miR-203 was decreased in SLE patients, indicating that miR-203 may play a role in the pathogenesis of SLE. And miR-203 may be associated with the occurrence of lupus nephritis.