This survey was conducted to investigate the relation of children's obesity index to their mothers' food habit during the October in 1995. The survey covered a total of 492 mothers whose children were in the fifth grade of elementary schools in Cheju City area. The results are summarized as follows: 1.The surveyed children's average WLI(Weight-Length Index) is 107.08. WLI shows that 16.1% of them are overweight, 16.1% obese and 49.8% ideally weighted. The mothers' average BMI(Body Mass Index) is 22.4. 21.8% of them are underweight and 69.4% normal. The children's obesity index is significantly correlated to their fathers', but not significant to their mothers'. 2.As to the food habit I (balance of nutrients intake), 58.4% of the mothers have 'excellent' or 'good' food habit and the mean score is 14.95 out of maximum possible score 24.0. Concerning to the food habit II (intake of sugar, fat and salt etc.), 87.4% of mothers have 'good' or 'fair' food habit and the mean score of is 13.34 out of maximum (possible score) 20.0. The mothers' food habit I and II, as a whole, have no significant effect on the children's obesity index, but in some items the significant relations are founded. The children's chesty index is significantly related to the intake of eggs (P<0.05) and pan-broiled or fried foods (P<0.05). The amount of mothers' food intake is significantly relevant to their obesity index (P<0.001), but not significantly to their children's. The food habit of mothers who have taken midnight snack almost every day are significantly related to their children's chesty index (P<0.05). The findings of the study emphasize the importance of the nutrition education to ensure health and better physical fitness for children and their mothers.