Abstract： Objective To analyze the diagnosis and therapy of pemphigus and pemphigoid.Methods Clinical data were retrospectively analysed for 648 patients with pemphigus or pemphigoid admitted in Huashan Hospital,Fudan University from 2003 to 2007.Results The mean age of onset of pemphigus was younger than that of pemphigoid(47.0±16.9 years vs 65.1±13.9 years.P＜0.001).Of 175 patients with pemphigus confirmed by direct immunoflorescence(DIF),100%were positive for IgG,and 92.0%for C3,while out of 223 patients with pemphigoid,51.12%were positive for IgG,99.1%for C3.For pemphigus,the consistency reached 68.8%among clinical diagnosis.pathological diagnosis and immunological(DIF)diagnosis,80.7%between pathological and immunological diagnosis.In the case of pemphigoid,the consistency was 62.8%among clinical,pathological and immunological diagnosis,and 78.1%between pathological and immunological diagnosis.Corticosteroids were primary treatment strategy for both pemphigus and pemphigoid.and prednisone of 0.5-1.5 mg per kilogram bodyweight per day could control the condition of most patients.Conclusions DIF could be used as an important diagnostic means for patients with pemphigus or pemphigoid which can not be confirmed by clinical manifestation or pathology.In primary hospitals,IgG and C3 are recommended for DIF testing when pemphigus is suspected,and C3 is recommended for suspected pemphigoid.