Abstract: Objective To understand the age,gender and regional differences of 20 meters shuttle run test(20 m SRT) in Chinese Han children and adolescents aged 7-18,and to provide scientific basis for improving the cardiopulmonary fitness level of the children and adolescents.Methods This study divided 26 provinces and autonomous regions into six regions (east,north,central south,northwest,southwest and northeast).A total of 17 280 children and adolescents were selected randomly as subjects of the research,and LMS method was used to construct a percentile graph according to their results of 20 m SRT.Results The 20 m SRT P50 values of boys and girls aged 7-18 years were between 13.87-43.23 and 13.30-28.76 laps,and the maximum oxygen uptake P50 values were between 43.12-46.57 mL/(kg · min) and 38.42-44.94 mL/(kg · min),respectively.The differences of 20 m SRT values of different age group among boys and girls(F=416.992,210.266) and VO2max (F=36.528,240.763) were of statistical significance(P<0.01),and those values among boys of the same age group were higher than those of girls(P<0.05).The mean values of boys and girls in each region were between 25.70-36.80 and 20.56-28.36 laps,respectively.In east,northwest,north,central south and northeast,20 m SRT scores increased with age,while boys and girls in the southwest region achieved better results from 7 to 12 years of age,and significantly decreased from 13 to 18 years of age.Conclusion The 20 m SRT scores of boys and girls increase with age,while the maximal oxygen uptake decrease with age.Boys' scores are higher than girls' in all age groups.The performance gap of boys and girls in the 20 m SRT and the maximum oxygen uptake began to widen from the age of 11-12.