The aim of this study was to investigate the relationships between cognitive functions and daily physical activities in primary school children. Subjects were 153 pupils (Age 6-12 years old), and visual Go/Nogo task for cognitive functions and parents questionnaire for daily physical activities were used. As results, male children exhibited negative correlation between duration of exercise and information processing time, and positive correlation between duration of exercise and the number of false response. Female children exhibited positive correlation between time of indoor play and number of false response. All these correlations were statistically significant. Further in females, those who spent longer time in playing video games exhibited statistically shorter reaction time. These findings suggested that the cognitive functions evaluated from visual Go/Nogo task were related to daily physical activities, especially the exercise and the indoor play. Further these factors and relationships could be different between males and females in preadolescent children.