Abstract: Objective To analyze the clinical characteristics of Bartter syndrome（BarS）and Gitelman syndrome（GitS）. Methods Clinical data of 36 adolescent and adult BarS and GitS patients during the past 28 years were retrospectively analyzed and compared. Results The mean age of 23 BarS patients（11 males and 12 females）was 30.6±9.86 years and the mean onset age of BarS was 28.5±9.58 years.The mean age of 13 GitS patients（12 males and 1 female）was 19.8±3.19 years and the mean onset age of GitS was 16.5±4.92 years.The main symptoms included weakness,polydipsia,polyuria,nocturia,paralysis,and tetancy in the two groups.The blood pressure of all patients was in normal range.The biochemistry test showed hypokalaemic alkalosis in all patients.The serum magnesium and urine Ca/Cr ratio in GitS patients was significantly lower than that in BarS patients.The fasting blood glucose level was higher in 3 BarS patients,but it was normal in all GitS patients.The renin-angiotension-aldosterone system was activated in all patients,but juxtaglomerular apparatus hyperplasia was observed in some patients（BarS 6/7 vs Gits 2/3）. Conclusion The clinical symptoms and biochemical changes in adolescent and adult BarS and GitS patients are similar,but the serum magnesium and urine calcium excretion levels are lower GitS patients in GitS patients.Glucose intolerable diabetes may be presented in BarS patients and GitS may be dominant in males.