The purpose of this study was to examine the dietary behavior of children according to their preference for fast food. The study was carried out on 470, 6th grade students (boys : 236, girls : 234) in September, 2002. The results are summarized as follows : The mean body mass index was 18.72 kg/$m^2$ for boys and 17.76 kg/$m^2$ $^2$ for girls. The subjective health disorder symptoms for the group preferring fast food was not significantly different than that of the other groups. The group preferring fast food consumed an inadequate volume of food, and they had an irregular and unbalanced diet. Their intake of green vegetables, vegetables, protein foods, and seaweed was significantly lower than that of the other groups. The food habit score for the group preferring fast food was lower than that of the other groups, and they had irregular meal times and had unbalanced diets. The group preferring fast food had a preference for sweet tastes, whilst members of the other group preferred a savory taste. The first choice for fast food by the group preferring fast food was hamburgers, the reason being that it tasted good. Results show that children who have a preference for fast food need to correct their dietary behavior. As a result, proper nutritional education and intervention is required in order to improve the consuming habits of children and their preference for fast food.