Objective To explore the clinical characteristics,relationship between treatment and prognosis of sarcoidosis and relationship of relapse to prednisone.Methods The clinical data of 165 patients with sarcoidosis were collected.The clinical characteristics,treatment process and prognosis,relationship of relapse with prednisone maintenance dose and course of treatment were retrospective analyzed.Results Among them,the most common involved systems were lung and lymph nodes.The involvement rates of lung,extra-thorax lymph nodes,cutaneous,ocular,salivary glands,liver & spleen,kidney and nervous system was 87.3％,51.5％,6.7％,6.1％,6.1％,4.2％,1.2％ and 1.2％ respectively.Unilateral tonsil,breast,ovary and bone involvement was seen in only 1 patient respectively with an involvement rate of 0.6％.A retrospective analysis was made for 114 cases with complete follow-up data.The mean follow-up period was (11.7 ± 5.7) (5-32) years.And 46 cases had no symptom on routine medical examinations.The most common consulted departments were respiratory,dermatological and general surgery departments.Among 74 patients on prednisone,48 patients (64.9％) were cured while 13 patients (17.6％) relapsed.Whereas in the observation group,25/38 patients (65.8％) remitted spontaneously and only 1 patient (2.6％) had recurrence.Relapse occurred more often in prednisone therapy group than in observation group (P ＜ 0.05).Longer prednisone 10-15 mg daily maintenance and a longer total course of treatment were associated with fewer recurrence(P ＜ 0.05).Conclusions The clinical manifestations of sarcoidosis vary and many patients have a self-limiting course.The most common involved systems are lung and lymph nodes.Stage Ⅰ / Ⅱ disease should be observed before prednisone therapy.Prednisone 10-15 mg daily for at least 6 months and a total course of treatment over 18 months may prevent relapse.