Background The incidence of postural tachycardia syndrome (POTS) has been increasing in children and adolescents,while clinical characteristics of POTS in the pediatric population are not fully understood.Methods An observational study was performed in 150 pediatric patients aged between 5 and 18 years who underwent head-up tilt test (HUTT) with the diagnosis of POTS at Peking University First Hospital from March 2008 to August 2013.Demographic data,clinical presentation,autonomic parameters,laboratory findings,and treatments were recorded.Results POTS in children commonly occurred in the age of 7-14 years.Dizziness (84.00％) was the most common symptom,followed by weakness (72.00％) and orthostatic syncope (62.67％).Positive family history of orthostatic intolerance (Ol) was found in 24.64％ of children with POTS.And 33.09％ of them had preceding infection history as precipitating events.Ten percent of them suffered from orthostatic hypertension.Hyperadrenergic status was documented in 51.28％ of 39 patients who were tested for the standing norepinephrine levels.More than half of POTS patients,with 24-hour urinary sodium level ＜124 mmol/24 hours,were suitable for treatment of salt supplementation.At least 25.74％ of POTS patients were of positive acetylcholine receptor (AChR) antibody.Low iron storage in children with POTS was relatively rare.Most patients responded well to treatments,43.51％ of patients recovered,while 7.63％ of them had relapse after symptoms disappeared.Conclusions POTS is a relatively common condition with complex pathophysiology and heterogeneous clinical manifestation.A comprehensive therapeutic regimen is recommended for the treatment.