Prevalence of obesity and dietary consumption of ten-year-old school children in Seoul were investigated. Three hundred forty boys and three hundred forty two girls from families of various housing pattern in Seoul were chosen for this study. Informations of the stduy were obtained from April 22 to June 11, 1985, by means of prepared questinnaires for general environmental factors, anthropometry for height, weigth and triceps skinfold theickness and interview to get 24 -hour food intakes of individuals. All the data collected were analyzed by using SPSS program. Average nutrients intakes of the subjects were satisfactory with respect toquality or quantity . Children from A group tended to consume more nutrients than B or C group. Physical growth of the subjects were similar to the ones for average school children in Seoul, but greater than korean national average. Children from A group were taller and heavier than B group whom were taller and heavier than C group . Prevalence of obesity were 15.7 % and 11.7 % of the subjects according to standards of relative body weight and triceps skinfold thickness. Higher prevalence were observed in boys than in girls and children from A group than B, and B group than C group. so therefore it could be summarized that children from A group consumed more nutrients, had better physical growth, and became obese more frequently than children from B or C.