After Hokkaido East Iburi Earthquake, longitudinal research data (2 weeks, 1 month, 2 months and 6months later) by questionnaire of junior high and high school student in the affected area were investigated. Data shows high school student represent higher than junior high school student’s stress level. And stress level is decreasing according to time elapse, however after big after-shock, most of stress level become higher than after first-shock, especially irritative and feel illness response. Stressresponse is easy to recover by stressful same event even after 6 month later.