Compared with the normal mice, the levels of immunoglobulin and complement deposition increased in SLE mice, and the immunofluorescence staining of the renal tissues showed positive signals for IgG, IgA, IgM, C3 and C1q at the same time, which is a characteristic immune pathological change for lupus nephritis. This evidence concerns the gene C3 and systemic lupus erythematosus.