The questionnaire was distributed to ten public elementary schools in Y City, Chiba, to investigate the children's developmental change of dietary habits, health awareness and nutritional knowledge. Data was collected from 364 children, who all completed the same questionnaire when they were in 4th, 5th, and 6th grade. There was no significant difference noted between the three graders as to the number of children who had breakfast every day; about 80% had breakfast regularly. However, almost 80% did not regulate their snack time. It is noted that the number of those who ate snacks as much as they liked increased between the 4th and 6th graders. About 80% talked with the other members of the family about their favorite meal, while more than 40% seldom talked with them about the kinds of snacks they liked. The number of those who recognized the intake of food was associated with their health increased significantly as they advanced in grade. By the 6th grade, 78.6% were aware that there was a relationship between food intake and health; understanding of the nutritional functions significantly increased as they advanced in grade. However, about 44% of the 6th graders under survey demonstrated a mixture of correct and incorrect nutritional knowledge. These developmental characteristics and relevant factors need to be considered in providing effective nutrition education for elementary school children.