Objective To design an effective, inexpensive and handy scoring system of preliminary screening for the diagnosis of orthostatic intolerance (OI) in children and adolescents. Methods Two hundred and seventy-four children or adolescents diagnosed or hospitalized in Children′s Syncope Specialist Clinic or Inpatient Department of the Second Xiangya Hospital of Central South University from July 2016 to March 2017, who were complaining about the following symptoms like unexplained syncope, dizziness, headache, chest tightness, chest pain, etc.The 274 cases included 141 males and 133 females aging from 5 to 18 years old with a mean age of (11.8±2.7) years.Each patient was asked to finish OI questionnaire and head-up tilt test (HUTT). The scores of the eight symptoms, including palpitation, headache, profuse perspiration, blurred vision or amaurosis, chest tightness, dizziness, gastrointestinal symptoms and syncope, were added as OI symptom scores.The data were analyzed by SPSS 18.0 software. Results All the patients were divided into HUTT negative group (n=151) and positive group (n=123). The positive group was composed of vasovagal syncope (VVS) (n=88), postural orthostatic tachycardia syndrome (POTS) (n=33) and orthostatic hypertension (OHT) (n=2). Among them, 31 cases were positive in baseline HUTT (BHUT) and 92 cases were negative in sublingual nitroglycerin-provocated HUTT (SNHUT). The mean OI symptom scores of HUTT positive group were distinctly higher than those of negative group [(6.4±4.6) scores vs.(3.5±3.4) scores, P=0.000] with significant difference.Taking score ≥2.5 as the borderline, the sensitivity and specificity of HUTT result prediction were 79.2% and 50.3%, respectively.Since the score was supposed to be integer number, HUTT result should be considered as positive when the score was ≥3.In the HUTT positive group, the scores of POTS children group were significantly higher than those of VVS group [(8.8±5.2) scores vs.(5.5±4.1) scores, P<0.01] and the mixed syncope had the lowest score in the VVS group; The scores of BHUT positive group were obviously higher than those of SNHUT positive group [(7.8±4.6) scores vs.(5.6±4.4) scores, P<0.05] and all the difference were significant. Conclusions OI symptom score has some predictive value on the results of HUTT and can be served as a preliminary screening of OI in children and adolescents. Key words: Orthostatic intolerance; Symptom score; Head-up tilt test; Child; Adolescent