The purpose of this study was to investigate the relationship between rebound jumping ability and running ability in preschool children. The subjects consisted of 166 preschool children (96 boys and 70 girls；age range：2.0-6.0 years). The measurements used were jumping height of counter movement jumping (CMJ), index (jumping height/ground contact time) of consecutive rebound jumping (RJ), 20-m running velocity (RV), step length (SL) and step frequency (SF). To exclude the effects of growth on running ability, dimensionless numbers：indices of running velocity (IRV), step length (ISL) and step frequency (ISF) were calculated. Results were as follows；1 ) CMJ jumping height, RJ-index, RV, SL, IRV and ISL increased with aging. 2 ) The IRV, ISL and ISF correlated with CMJ jumping height and RJ index. The coefficient correlation of RJ-index to increase with aging. 3 ) RJ height and RJ ground contact time correlated with flight time and ground contact time in the 20-m run. These results suggest that CMJ and RJ ability influence the development of running ability in preschool children.
