The present study was designed to investigate the kinematic factors related to sprint running velocity. The subjects were 71 sprinters(49 males and 22 females)who ranged from world class to collegiate level. Movements were recorded around the 60-m point from the start line during a 100-m race(during official races including world championships in athletics, or under experimental conditions)using 16-mm movie or video cameras. The official best time during recording of the movements was 9.86. The correlation coefficients between kinematic data(see Fig.1)and sprint running velocity were calculated for three groups(male, female, and all sprinters). Step length and step length index(step length/body height to exclude the effects of body height)were correlated positively and significantly with sprint running velocity for all groups(male, female, and all sprinter). Step frequency and step frequency index[step frequency・(body height/gravitational acceleration)^<1/2>to exclude the effects of body height]were correlated positively and significantly with sprint running velocity for all groups except male sprinters with regard to step frequency. With regard to leg swing, maximal thigh angle and maximal leg angle showed no significant correlation with sprint running velocity, but the minimal knee angle showed a singificant negative correlation with sprint running velocity for both male and all sprinters. These results suggest that the purpose of high knee drills generally carried out during training needs to be reconsidered. The maximal leg touch down velocity showed a significant positive correlation with sprint running velocity for both female and all sprinters. This probably means that the leg touch down velocity acts to reduce the deceleration at the moment of foot contact and to accelerate the subsequent leg swing back velocity during the foot contact phase. As for the support leg, the maximal leg swing velocity showed a significant positive correlation with sprint running velocity for all groups. Although the maximal hip extension velocity during the foot contact phase was correlated positively and significantly with sprint running velocity for male sprinters, the maximal knee and ankle extension velocity showed a significant negative correlation with sprint running velocity for female and all sprinters. These results suggest that the knee should not be extended to transfer the hip extension velocity effectively to the leg swing velocity during the foot contact period. This was borne out by the fact that the top sprinters entered in the present study hardly extended the knee of the driving leg during the foot contact phase.