According to the age intervals of 9 to 12, 12 to 15, and 15 to 18 years, 365 rural adolescents, who were subjected to the foregoing studies of aerobic work capacities, were divided into the three age groups for male and female respectively. The correlation matrixes in 27 variables were made and the factor analyses were also tried. The results obtained were as follows: 1) Correlations of physiques and Vo_2max (l/min) were positive, and males showed higher correlations than females. The correlation for female in the age group of 15 to 18 years was extremely low. 2) In correlations between skinfold thicknesses and Vo_2max (l/min), no significant correlations were found for males with regard to upper arm and also for females concerning upper arm and waist. Except the above sites males indicated significant positive correlations in the age groups of 9 to 12 years and 12 to 15 years for males but a positive correlation was brought about only in the age group of 15 to l8 years for females. 3) Correlations of skinfold thicknessses and Vo_2max (ml/kg/min) were of no significance in the age groups of 9 to 12 years and 12 to 15 years for males, but a significant negative correlation was shown in the age group of 15 to 18 years. On the other hand negative correlations were found in all age groups for females. 4) For males correlations of skinfold thicknesses with 1500-meter endurance run results were found to be negative in all age groups only on the upper arm. 5) Correlation coefficients of Vo_2max (l/min) and Vo_2max (ml/kg/min) were positively higher in more advanced age groups for males. But females showed pronounced high positive correlation in the age group of 15 to 18 years. 6) Males showed heigher positive correlations between Vo_2max (l/min) and endurance run than females. 7) Negative correlations of oxygen removals and respiratory quotients were indicated in both sexes, and no differences were found in the sexes and in age groups. 8) The factor analyses implied that, except the common and fundamental factor of endurance type of running, the factor of respiratory efficiency upon oxygen removal and respiratory quotient was firstly preceded in males but in females the respiratory efficiency followed the factor of skinfold thickness. The factor analyses also suggested that the oxygen removal was of great importance for aerobic work capacities.