A study was conducted to clarify the effects of running long jump practice in physical education classes for 11-or 12-year-old elementary school children. The subjects were divided into two groups: a training group (9 boys and 8 girls) and a control group (10 boys and 12 girls). The training group performed long jump practice over a period of 2 weeks (5 physical education classes), while the control group performed gymnastics practice. The jumping distance and 50-m sprint time were measured in both groups to clarify the performance before and after the corresponding period. In addition, the training group underwent measurement of approach running distance, approach running speed, take-off leg and jumping motion by angular kinematics. It was found that the jumping distance of the training group increased significantly for both boys and girls. However, no significant changes were found in the control group. After training, the approach running distance in the training group decreased significantly for both boys and girls. After training, there were significant positive correlations between the change in jumping distance and the change in approach running speed in the training group in the sections from 5 to 0 m before take-off in both boys and girls. In addition to the girls, there were significant positive correlations between change in the jumping distance and the change in approach running speed in the sections from 15 to 10 m and from 10 to 5 m before take-off. For boys in the training group, the relationship between the increase in jumping distance and the speed at touch down was significantly positively correlated with take-off. For girls in the training group, there was a significant positive correlation between the increase in jumping distance and the speed at touch down. From these results, it is suggested that long jump practice for 2 weeks (5 times) would improve the jumping distance of sixth-grade elementary school children.