In order to investigate food purchase frequency of elementary school children and its related ecological factors, 4314th, 5th and 6th grade elementary school children and their mothers, living in Seoul and Daejon, small city and rural area of Chungnam Province, were participated in this study. The subjects and their parents were surveyed by a selfrecording questionnaire about food purchase frequency and some ecological factors. Average height and weight of the subjects by gender and grade were similar to or a little bit more than the 1998 Korean Growth Standard. According to relative body weight, 30.6% and 10.8% of the subjects belonged to under-weight and obesity categories, respectively. Of the subjects, 46.9% used PC telecommunication or internet, 53.8% of them used it for less than an hour per day, and 46.4% watched TV for 2 to 4 hours a day. About 42% of the subjects spent 500 Won or less daily to buy snacks. A half of the subjects took snacks once a day because of hunger. Mothers' nutrition knowledge score was averagely 8.16 out of 13 full score and the average attitude score was 43.22 out of 50 full score. Foods purchased more than once a week were milk and yoghurt, cookies, ice-cream, ramyun, and gum in order. Family income, parents' education level, mothers' nutrition knowledge and food attitude score, students' snacking frequency and TV watching time showed significant correlations with purchase frequencies of some individual food items. In conclusion, the elementary school children considered taste most important rather than nutrition in buying snacks and most frequently bought carbohydrate foods and concentrated sugars except milk. Ecological factors such as mothers' nutritional knowledge and food attitude, TV watching time and snacking frequency had influenced the children's food purchase frequency. Accordingly, it is necessary to educate both children and their mothers about good food purchase and the importance of snacking.