Aerobic work capacity (Maximal oxygen consumption, Vo2) in various countries has been determined by using tread-mill walking and running. Since both incremental and constant loading procedures have been used in determining Vo2 rnax., it is considered to be the best index of work capacity and of maximal cardiovascular function. This study is concerned with the measurement of maximal aerobic work capacity of P.-E.-majored male students by using Dr. Robert Bruce's maximal tread-mill exercise protocol. 38 sophomore P.-E.-majored male students were screened as Volunteering subjects in the study on the basis of comparison of Vo2 max. The subjects live at men's dermitory and go about their usual routines freely; however, they keep their physical activities and study schedule. Their physical characteristics are listed on table I. We also divide those subjects into four groups according to the suggestions of Saltin and Astrand. High group's Vo2 max. is over 60ml/kg/min., Fair group is over 55ml/kg/min., average group is over 50ml/kg/min., and poor group is over 45ml/kg min., respectively. We use the F-ratio to test the Significant Level for the subjects' parameters and Vo2 max. Except Vo2 max. (P < 0.01) and oxygenremoval ratio (P approach 0.05), we find that the ratio exerts no significance no body weight, body height and maximal heart rate. Duncan's multiple range test is used to test the significant range of Vo2 max. and oxygen removal ratio. We list the analysis materials on appendices A, Band C. Finally, we also figure four groups' Vo2 max. accumula-tion in the last five minutes to understand the increase rate to the maximal. From the slope of the Vo2 max. accumulation, we find that those subject's' increase rate varies from person to person, and B alke's exercise intensity (more than 60%) can be accepted in our country.