In study I, Locus of Control Scale developed by Kambara et al. (1982) was administered to 4310 junior high school students, 1416 senior high school students and 1837 college students. By regression analysis, it was found that older students had more external scores than did younger students. In detail, perceived effectiveness of effort showed a relatively great decrease. On the other hand perceived self-determination did not show significance decrease with age. In study II, additional questionnaires concerning attitudes and behaviors in school were administerd to both junior and senior high school students. Older students reported more depressive feelings correlating with internal external locus of control scores.