Objective: The aim of this study was to observe the changes in cardiorespiratory fitness after high intensity interval training(HIIT), and to provide a reference basis for scientific and reasonable sports plans. Methods: A total of 26 female college students with sedentary lifestyle were randomly allocated into MCT group (n=13) and HIIT group(n=13). All the participants undertook a graded exercise test to obtain VO 2max. The MCT group was trained with 60% VO 2max intensity for 30 min, while HIIT group received exercises with 90% VO 2max intensity every 3 min, intermittent 2 min, for 6 sessions three times a week for 8 weeks. Before and after 8 weeks of training, the subjects were tested for body shape, cardiorespiratory function and aerobic exercise capacity. Results: BMI[(22.34±2.73)(21.56±2.39)kg/m2], percentage of body fat [(31.43±5.65)%, (28.85±5.52)%] of HIIT group and BMI [(22.98±3.23)(22.35±3.09)kg/m2], percentage of body fat [(33.15±4.48)%, (31.48±4.73)%] of MCT group showed significant changes before and after training(P<0.01). For cardiorespiratory function, there was a significant change in VC [(3.30±0.60)(3.61±0.54)L], vital capacity index(56.22±10.73, 63.51±10.53), and MVV [(81.44±20.45, 91.17±15.64)L/min] in HIIT group. There was also a significant change in VC [(3.08±0.41)(3.19±0.36)L] and vital capacity index (52.74±8.66, 55.62±7.88) in MCT group, and there was a significant difference between the two groups(P<0.01). In terms of aerobic exercise capacity, maximal oxygen uptake in HIIT group [(2 204.15±232.39)(2 539.23±339.39)mL/min] and MCT group [(2 136.15±240.76)(2 462.00±318.29)mL/min] increased significantly after training(P<0.01). Conclusion Both HIIT and MCT can significantly improve lung function and aerobic performance of sedentary female college students, but HIIT is found more effective than MCT training.