Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breaking of tolerance to nuclear self-antigens and the production of autoantibodies. This complex and challenging disease can involve several organs in the body such as the joints, skin, kidney, eyes, heart, and muscles. CD163 is a 130 kDaprotein .It is a transmembrane scavenger receptor for hemoglobin-haptoglobin complexes and is expressed exclusively on macrophages and monocytes. It contributes to the prevention of oxidative stress and inflammation associated with extracellular metabolism of hemoglobin. In addition to the membrane CD163, a soluble form of CD163 (sCD163), which is produced by shedding of CD163, is present in blood and various tissue fluids. The major function of M2 macrophages is resolution of inflammation, tissue remodeling, and promotion of fibrosis. The chief anti-inflammatory cytokines secreted by them are IL-10, arginase-1, and transforming growth factor–β. M2 macrophages have been thought to play key pathogenic role in development of various autoimmune diseases including SLE. Since these macrophages express CD163 which can be proteolytically cleaved from the surface and released in the circulation as a soluble protein, soluble CD163 (sCD163) may correlate with disease activity. sCD163 may participate in the immunopathological process of lupus nephritis(LN) as an inflammatory mediator. Serum sCD163 levels correlate with the severity of LN and are an important indicator of poor renal prognosis in patients with LN, suggesting that macrophage activation is involved in the development of LN. Serum sCD163 shows potential as an effective biological marker for LN diagnosis, differential diagnosis and prognosis evaluation.