In our ongoing research project concerning lifestyles and snack-selection behavior, the questionnaire surveys of children/students has been conducted in northern Thailand since 1997. Three regions, the urban Chiang Mai, the rural Samoeng, and the mountain village of Bokaeo, linked together by a communal information route, were newly chosen as a survey area of the present study. Regional difference and school grade difference (primary, secondary and high schools) within respective regions were also examined. In the urban area, 'keeping late hours' was recognized in the higher grades. The rate of 'missing a morning meal' was higher in Chiang Mai and Samoeng. Inclination to dietary consciousness towards being overweight widened in the lower grades in the urban area. Meanwhile, this inclination can be observed in the rural higher grades, but surprisingly none at all in the mountain village. Regional differences were remarkable in the money spent on snacks, the variety of snacks taken, and the frequency of snack ingestion. In the snack selection criterion and behavior conducted by the correspondence and cluster analysis, Bokaeo occupies the most remote position, while Samoeng is rather close to Chiang Mai, following trends of Chiang Mai. It is to be noted that the second grade of the high schools in Chiang Mai shows progressive features.