Objective: To understand the correlation between physical activity (PA) and socioeconomic status (SES) among Chinese children and adolescents, and to provide theoretical basis for physical activity promotion for Chinese children and adolescents. Methods: By using stratified random cluster sampling, a total of 4 269 children and adolescents aged 7 to 18 were selected from six cities in China from September to December 2018. Physical Activity Level Evaluation Questionnaire of Chinese Children and Adolescents Aged 7 to 18 was used to investigate PA and SES, and the height and weight were measured. Methods: In terms of different intensity of PA, the time spent on light intensity physical activity(LPA), moderate intensity physical activity(MPA), moderate to vigorous physical activity(MVPA)and total physical activity(TPA) in low SES group was 28.5(6.9,57.1) min/d, 46.2 (25.7,79.2) min/d, 61.4(34.3,101.9) min/d and 102.9(65.0,145.8)min/d respectively, which was higher than that in middle SES groups [ 21.4 (4.3,50.7), 37.1(18.6,65.7), 50.3(27.1,86.8), 85.7(49.3,127.1) min/d] and high SES groups [24.3( 5.0 ,54.3), 40.0(21.4,69.1), 54.3(32.9,91.4), 89.6(55.7,132.9) min/d]( P <0.01). In terms of different types of PA, the traffic PA [40.0(15.0,68.6) min/d] and entertainment PA[4.3(0,17.1)min/d] accounted the highest proportion in low SES group,while sports PA [36.4(20.7,60.7) min/d] accounted the highest proportion in high SES group( P <0.01).The compliance rates of MVPA in low, middle and high SES groups were 51.1%, 42.5% and 45.2%, respectively, and the differences were statistically significant ( χ 2= 22.02 , P <0.05). After controlling for confounding factors, the detection rate of MVPA in the low SES group was 1.24 times higher than that in the high SES group ( P <0.01). Conclusion The MVPA and TPA time of children and adolescents with middle SES group were the lowest. Physical activities spent on traffic and entertainment account highest in low SES group, while physical activities spent on sports account highest in high SES group.