OBJECTIVES: The purpose of this study is to compare the performance and the endurance difference based on different situations of Yo-Yo intermittent endurance test in Macau soccer and hockey players. Additionally, by means of examining the correlation between maximal O2 uptake ( O2max) and Yo-Yo performance, the validity in evaluating individuals’ aerobic capacity is also investigated. METHODS: 29 young athletes aged 16 – 26 years old (15 soccer and 14 Hockey players), who have never taken “Yo-Yo” test, were recruited to participate in this study voluntarily. For soccer and hockey players, the mean training years were 5.40  1.84 yr and 4.64  0.93 yr (P>0.05), while the training times were 4.00  1.25 and 3.43  1.09 respectively. RESULTS: It was found that, 1) the performance of Yo-Yo test was poor in Macau soccer and hockey players, 2) there were no differences in Yo-Yo performance upon sports and field situations in spite of a better trend in middle fields than forwards and backwards, 3) it has a highly significant relationship between O2max and distance of Yo-Yo (r=0.76 - 0.78, P<0.01). CONCLUSION: It suggests that aerobic fitness should be strengthened in Macau soccer and hockey athletes, especially in backwards. “Yo-Yo” Intermittent Endurance Test is a valid test to express the endurance capacity of soccer and hockey athletes.