Objective:To observe immunological indexes,the quantity of cytokine expression and clinical curative effect of umbilical cord mesenchymal stem cells between before and after the treatment of systemic lupus erythematosus patients.Methods:Selected 10 cases of SLE,on the basis of glucocorticoid and immune inhibitor treatment,intravenous injection UC-MSC of cultivating proliferation within 6 generations.Before and after treatment of UC-MSC testing the relative quantity of cytokine of CTLA-4,IL-15,IL-2,CD86,IL-17c,Foxp3,TGF-β2 which were related of immunopathogenesis of SLE.Before and after treatment to determined SLE disease activity index (SLEDAI) score and detection of blood in the urine routine,liver and kidney function,24 hours urinary protein quantitative,immunoglobulin and complement levels.Results:After treatment the relative expression value of IL-15 and IL-2 was decreased,CTLA-4 was risen.There had no significant difference with the relative expression value of CD86,IL-17c,Foxp3,TGF-β2 in before and after treatment of UC-MSC.After treatment serum complement C3 and C4 level,serum albumin,were risen.24 hour proteinuria and SLEDAI were decreased.There was no serious adverse reaction occurred,no complications related to transplantation in 10 cases.Conclusion:UC-MSC can regulate the expression of cytokines of participate in the immune response in the patients with SLE.Treatment of SLE by UC-MSC can elevate serum albumin and C3 and C4 level,reduce the 24 hours urinary protein quantity,relife kidney damage,improve clinical symptoms;UC-MSC transplantation in patients with SLE have good security;UC-MSC transplantation may be a feasible method for the treatment of SLE.