A survey was performed on 466 high school students and 403 university students. 86% of high school students and 89% of university students estimated their customary sleep time to be 6-8 hours. Although there was no significant difference between high school students and university students with awake time, bed time was later for university students than high school students. So that sleep time was shorter for university students. Also there was more regular sleepers for high school students and more irregular sleepers for university students. Although university students included more good sleepers and were satisfied with their sleep more than high school students, there were more students to have daytime naps for university students. These results suggest that to take favorite retiring and awaking time was necessarily no good for taking sleep of good quality.