The purpose of the present study was to clarify the effects of sprint practice in physical education classes for 11- or 12-year-old elementary school children.The subjects were divided into two groups;a training group(12 boys and 8 girls)and a control group(13 boys and 8 girls).The training group performed sprinting prectice such as the starting dash and full sprint over a period of 2 weeks(6 physical education classes), while the control group had no special practice.The 50-m sprint time was measured to clarify the performance before and after the corresponding period in both groups.The training group was measured for sprint performance such as mean speed, mean step frequency, and mean step length every 10 m from the start up to 50 m.The results obtained were as follows:The 50-m sprint time of the training group decreased significantly for boys as well as girls.However, no significant changes were found in the control group.After training, the mean speeds in the training group in the sections from 10 to 20 m and from 40 to 50 m increased significantly for boys, and increased significantly in all the sections except from 20 to 30 m for girls.After training, for boys in the training group, the mean step length increased significantly from 10 to 20 m, from 30 to 40 m, and from 40 to 50 m, but the mean step frequency did not increase significantly.For girls in the training group, the mean step length increased significantly from 10 to 20 m, from 30 to 40 m, and from 40 to 50 m, and the mean step frequency increased significantly from 30 to 40 m and from 40 to 50 m.From these results, it is suggested that sprint practice for 2 weeks(6 times)should improve the sprint performance of sixth-grade elementary school children.