This study investigated the relationship between physical activities (motor quantity，fundamental movement) during free play in nursery school of ４ years old children and motor abilities，recording by lifecoda and videocamera．
The result were as follows；
1） The analysis of motor quantity showed that the number of steps and activity intensity were apt to change depending on children's motor abilities；the number of steps and activity intensity of children with higher motor abilities were higher，and those of children with lower motor abilities were lower．
2） The analysis of fundamental movement revealed that children with high motor abilities showed higher frequency of movement．However，variation of movement didn’t change whether children’s motor abilities were high or low．
The number of steps，activity intensity，and frequency of movement showed a significant relationship with the motor abilities of children，while the variation of movement had no relationship with it．
