Research purpose: To investigate the effect of hypoxia and normoxia on heart rate variability(HRV) and blood pressure(BP) after 5 weeks of high-intensity interval training (HIT) in female collegiate students. Research method: 24 female collegiate students, who didn’t have regular exercise previously, were recruited to participate in the study. The basic characteristics of age, height and BMI were 20.9±0.6 years, 163.2±0.8 cm and 25.8±0.5 kg/m2. They were divided into 2 groups randomly, which were normoxic HIT group (NC-HIT) and hypoxic HIT group (HC-HIT). Exercise intervention lasted for 5 weeks with 4 days/week and 60 8-12s cycling exercise/day. The initial load was 1 kg, and if the whole 60 groups were finished in 2 continuous times, the load was increased by 0.5 kg. The oxygen content in HC-HIT was equal to 2500 meter altitude. Before and after the intervention, an 8-12s HIT test with 1kg load were conducted respectively. Sitting BP were recorded at the time points of 20min before HIT and 5, 10, 20, 30, 40, 50, 60min after HIT. Sitting HRV was recorded at 20min before HIT and 5, 20, 40, 60min after HIT, while exercise HRV was also recorded. Supine BP and HRV were recorded at 20min before HIT and 90min after HIT. Research results: 1) Compared with pre-test, LFn and LF/HF were significantly decreased, and HFn was significantly increased at pre105min in post-test. At pt20-60min, LF/HF was significantly decreased, and SampEn was significantly increased. Tri-index was significantly increased at pt20-40min, and exercise MeanHR was significantly decreased (p <.01). Diastolic BP (DBP) was significantly decreased at pre20min and pt90min, but systolic BP (SBP) didn’t have significant difference (p >.05). 2) Compared with NC-HIT, tri-index was significantly increased at exe0-5min. At exe5-10min, LFn and HFn were significantly different (p <.05). Before and after HIT, HRV and BP didn’t have significant differences (p >.05). Research conclusion: 5 weeks of HIT can improve HRV and DBP in 2 groups, but had no effects on SBP. Hypoxia training in improving HRV and BP remains to be further studied.