Objective: To explore the relationship between junior high school students lifestyles and 20 m shuttle run test (20 m SRT) performance, so as to provide a theoretical basis for promoting a healthy lifestyle among junior high school students. Methods: From April to June 2021, a total of 2 397 junior high school students aged 12-17 years in Yushan, Wuyuan, Hengfeng and Yugan counties of Shangrao City, Jiangxi Province were selected by random cluster stratified sampling. A questionnaire survey and 20 m SRT test were conducted. Logistic regression analysis was used to explore the association between lifestyles and 20 m SRT scores. Results: The passing rate of 20 m SRT for middle school students was 83.3%. Chi square test results showed that there were statistically significant differences between gender, grade, household registration, type of schooling, father s education and the 20 m SRT scores of junior high school students ( χ 2=25.26, 25.04, 6.99, 7.96, 16.22, P <0.05). Significant differences were found in 20 m SRT scores between vigorous and moderate physical activity and breakfast behavior in the last seven days ( χ 2=6.78, 6.29, 9.13, P < 0.05). The results of Logistic regression analysis showed that after controlling for confounding factors, "no vigorous physical activity in the last seven days" was positively correlated with the lower performance of 20 m SRT ( OR =1.31, 95% CI =1.03- 1.67 , P < 0.05). "Breakfast skipping" was positively correlated with 20 m SRT lower performance (frequent eating, OR =1.37, 95% CI = 1.09 -1.73, P <0.01). Conclusion Vigorous physical activity and regular breakfast consumption behavior are associated with higher performance 20 m SRT of junior high school students. Schools should encourage students to develop a habit of actively exercising and consuming breakfast regularly in order to ensure the healthy development of cardiopulmonary endurance levels.