Acquired hemophilia A (AHA) is anunusual disease resulting from autoantibodies (inhibitors) against coagulation factor Ⅷ (FⅧ) and clinically manifests as bleeding, which sometimes can cause potentially limb-threatening or life-threatening situations. AHA is associated with cancers, auto-immune disorders, infections, dermatologic conditions and certain medications, among which it is commonly secondary to multiple rheumatologic conditions,such as rheumatoid arthritis, systemic lupus erythematosus (SLE), pollymyositis, autoimmune hemolytic anemia and undifferentiated connective tissue disease. In autoimmune diseases, it may be the result of autoantibody producing against FⅧ, and some cases of AHA may act as the first manifestation of SLE. AHA should be suspected in patients who have spon-taneously hemorrhagic events with an isolated prolonged activated partial thromboplastin time (APTT), reduced FⅧ activity and a negative lupus anticoagulant (LA). When FⅧ inhibitor is found, it can be diagnosed. The management of AHA focuses on the following goals: (1)controlling and preventing blee-ding,(2)eradication of the inhibitor,(3)treatment of the underlying disease. Here, a case of AHA in a patient with lupus is reported. A 53-year-old man with a 4-year history of SLE developed arthralgia and ecchymotic skin lesions after arthrocentesis of knee joint. Ultrasound confirmed the presence of an intramuscular hematoma. Coagulation tests revealed that FⅧ activity reduced to 1% and a prolonged APTT (92.2 s), FⅧ inhibitors were found to be as high as 60.0 Bethesda Units. Initial treatments with me-thylprednisolone 200 mg/d were started but new hemorrhagic manifestation occurred and hisbiological indexes were not good. Then the patient was treated with intravenous pulse corticosteroids (methylprednisolone 500 mg/d),intravenous cyclophosphamide, and also plasma and prothrombin complex infusion. Sub-sequently, FⅧ activity returned within normal ranges, FⅧ inhibitors decreased and clinical improvement was significantly obtained. The patient’s condition kept stable till now.Hemorrhagic events due to produc-tion of antibodies directed against coagulation factors were rarely observed in SLE and attentions should be paid to the association between SLE and AHA.Bypass treatment was considered as the immediate antihemorrhagic treatment. Corticosteroid combined with immunosuppressor was recommended as the main therapy to eradicate the inhibitors. However we still lack the therapeutic guide-lines and standar-dized treatment in patients of AHA with SLE at present.