This study investigated Korean elementary school children''s happines by gender and grade and by attendance in after-school programs during weekdays and weekends. Participants were 3,608 children in Korean provincial areas except Jeju-do; they responded to the Happines Scale developed by the researchers. Data were analyzed by frequency, percent, and t-test. Results were(1) children''s happiness level was high; girls'' happiness level was higher than boys''. As they moved up in school grade, happiness level was higher than boys''. As they moved up in school grade, happiness level decreased. (2) Their attedance in after-school programs during weekdays and weekends decreased their happiness level in leisure and extra academic activity, but it increased happinesss in school/community life and sibling relations. Conclusions were that reduction in the amount of children''s after-school programming would increase children''s happiness.