Objective: Decline of sports ability in Japanese children is a recent problem. It has also been pointed out that the development of Japanese children's frontal lobe function had recently been delayed. Several factors including playing experiences are suspected to be involved to these phenomena. This study attempted to clarify the relationships among sports and playing-experiences, sports ability and frontal lobe function in Japanese kindergarten children.<br>Method: A total of 171 upper-grade kindergarteners of three kindergartens in K city, Kagoshima prefecture, were investigated by questionnaires to their parent in April, 2006. Tests of frontal lobe function (GO/NO-GO task and SCG: shape choice game test), sports test (including 8 items), and evaluation for ADHD (attention deficit and hyper activity) tendency by the class-teachers were also administered in April, July and November, 2006.<br>Results: Frontal lobe functions and sports ability tended to correlate positively with outdoor body using play experiences, and negatively with indoor personal play experiences. Relationships between several sports test items and frontal lobe functions or ADHD tendency were observed in cross-sectional analyses. Higher frontal lobe function was correlated with strong hand grip, high upper body lift, longer one-foot balance with opened eyes.<br>In the longitudinal analyses, most test performances in both of frontal lobe function and sports ability had improved seven months later. Improvement of frontal lobe function was correlated with improvement of upper body lift, standing broad jump. Improvement of hand grip was larger in the two kindergartens where intervention with traditional hand using play was administered.