Objective: To discuss the correlation between aerobic exercise ability, pulmonary function and heart rate recovery ability of 7-12 year-old students under different altitudes, so as to provide evidence on the physiological changes of exercise and characteristics of altitude training among children and adolescents at different altitudes. Methods: A total of 235 students aged 7-12 years old living at 3 240 m(Hi group), 300 students at 1 290 m(SubHi), and 300 students living between 1 290 m and 3 240 m (HiSubHi) were selected to perform 20-mSRT test, respiratory function test and heart rate recovery ability evaluation after quantitative load exercise. Results: Performance on 20-mSRT, FVC, FEV1, FEV1% and V% of students aged 7-12 years at different altitudes showed an upward trend with the increase of age. After adjusting for altitudes, there were significant differences in average level of these indicators. Average level of 20-mSRT, FVC, FEV1%, FEV1% and V% in SubHi group were significantly higher than those in Hi group(P<0.05), and the HiSubHi group showed an upward trend compared with Hi group after 1-year adaptation to the sub-highland environment; Except for male FVC (r=0.33, P=0.24) and FEV1 (r=0.34, P=0.22) in HiSubHi group, and the male FEV1% (r=0.46, P=0.14) in SubHi group, all the indicators showed significant association with 20-mSRT(P<0.05); 20-mSRT was only significantly correlated with heart rate recovery ability among SubHi group (male: r=0.78, P<0.05); Female(r=0.81, P=0.01), there was no significant correlation between 20-mSRT and heart rate recovery ability in other groups(P>0.05). Conclusion The results suggest developmental characteristics of aerobic exercise ability, lung function and heart rate recovery ability among 7-12 years old students under different altitudes. The correlation among 20-mSRT, FVC, FEV1, FEV1% and V% might involve high altitude adaptation.