BACKGROUND: Generally VO2 max is higher in treadmill exercise than cycle ergometer exercise. According to Hassen and Wasserman, VO2 max with treadmill exercise is higher at ratio of 1.11 than that with cycle ergometer. VO2 max also is influenced by race, sociocultural background, exercise habit. In this study, VO2 max and AT were evaluated between Treadmill and cycle exercise in male Korean college students. METHOD: Study subjects were 44 male college students. We randomized them into 2 groups; 24 students did treadmill exercise at first and 1 week later did cycle ergometer. Another 20 students did in opposite method. They made symptom limited maximal exercise. Author defined maximal exercise as followings: 1) respiratory exchange ratio(RER)>1.1, 2) plateau>30 sec, 3) heart rate reserve(HRR)<15 %, or 4) breathing reserve(BR)<30 %. Otherwise their results are excluded as submaximal exercise. Anaerobic threshold(AT) was estimated by V-slope method. RESULTS: VO2 max and AT was 45.1 +/-6.66 ml/kg/min and 26.0 +/- 6.78 ml/kg/min in treadmill and 34.9 +/- 5.89 ml/kg/min, 19.5 +/- 4.77 ml/kg/min in Cycle Ergometer. The measured-VO2max/pred-VO2max was 98.8 +/- 13.24 % in treadmill; 84.4 +/- 13.42 % in cycle ergometer. Comparing VO2 max in treadmill with that obtained by Hassen's method, there were significant differences.(p<0.01). At maximal exercise HRR, O2/pulse, BR, VE/MVV, VE/VCO2 were higher in treadmill than in cycle but VE/VO2, Vd/Vt, Ti/Ttot were not. At AT O2/pulse, BR, VE/MVV, Ti/Ttot, were higher in treadmill than in cycle, otherwise not. CONCLUSION: According to the result of this study, there are larger gap between treadmill and cycle ergometer in normal Korean adults than foreign data, and it needs further study to obtain reference value of Korea.