Objective: To explore the effect of long term aerobic exercise on microcirculation function and VO 2max of college students, and to explore the relationship between microcirculation function and VO 2max . Methods: Seventy sports major college students were selected as the exercise group, 70 sedentary non sports major students were selected as the control group. PF6000 dual channel laser Doppler blood flow detector was used to assess the skin microcirculation function on the quadriceps femoris muscle of the subjects right lower limbs.The PFT Ergo cardiopulmonary function test system and the equipped power bicycle were used to measure the VO 2max of the subjects. Results: The baseline value of MBP in the exercise group was significantly lower than that in the control group (6.5±1.8 vs. 8.1±2.5), but the microvascular reactivity(1 666.3±588.6 vs. 1 165.2±407.1) was significantly higher than that in the control group(t =-3.42，4.46， P <0.01). The absolute value of VO 2max (2 684.8±451.1 vs. 2 474.4±423.5) and relative value (42.7±4.3 vs. 35.1±4.8) in exercise group were significantly higher than those in control group( t =2.16，3.25， P < 0.01 ). Multiple regression showed that there was a positive correlation between microvascular reactivity and VO 2max (relative value) ( β = 0.40 , P =0.03), but no significant correlation between percutaneous oxygen partial pressure and VO 2max (relative value) ( β= 0.23 , P =0.19). Conclusion Long term physical exercise can decrease microcirculation perfusion volume, improve microvascular reactivity, percutaneous oxygen partial pressure among college students. Improvement of the microvascular reactivity may be a sport improving VO 2max (relative) one of the most important peripheral physiological mechanism.