This paper compares the nutritional status of left-behind and non-left-behind middle school students in central China, analyzes the association between nutritional status and cardiopulmonary endurance of middle school students.This paper adopts a randomized whole group stratified sampling method to test the height and weight of 3320 middle school students aged 13-17 years old in Jiangxi Province, using the 20m SRT for cardiopulmonary endurance level testing. The association between different nutritional status and 20m SRT performance was explored by one-way ANOVA and logistic regression analysis.The detection rate of boys in the normal nutritional status group was statistically significant (p < 0.01), as the detection rate of left-behind students was less than that of non-leave-behind students. The 20m SRT results of male and female students were all in the normal>emaciated>overweight and obese group. Logistic regression analysis showed that the 20m SRT performance failure detection rate was positively correlated with overweight and obesity, with the failure detection rate in the wasting and overweight and obesity groups being 1.06 (95% CI = 0.89-1.27) and 1.61 (95% CI = 1.16-2.22) times higher than that in the normal group. In the group of male middle school students with normal nutritional status in central China, the detection rate of left-behind middle school students was lower than that of non-left-behind middle school students. The level of cardiopulmonary endurance was higher in normal nutritional status middle school students than in emaciated, overweight and obese middle school students, and overweight and obesity were negatively correlated with cardiopulmonary endurance. Key words: Left-behind Middle School Students, Non-left-behind Middle School Students, Nutritional Status, Cardiopulmonary Endurance