The purpose of this study was to investigate the effect of knowledge and practice of diet therapy on diabetic control in Insulin-dependent Diabetics. The subjects were 31 patients (male 15, female 16) aged 7 to 16 years old who participated pediatric health camp. The average of diabetic of diabetic duration was4.2 years. 48.4 % of subjects has the motive to diabetics diagnosis because of 3-plentiful symptom in both group. The average of height was 151.5 cm for male and 141.4cm for female, the average weight was 43.1 kg for male and 38.6kg for female. In PIBW, underweight was 53.3 % for male, 37.5% for female, normal weight was 40.0% for male, 56.3% for female. The fasting blood glucose was 173.5mg/dl males, 202.9mg/dl for females, Postprandial blood glucose was 138.8mg/dl for males, 194.3mg/dl for females. Energy intakes were 2,100 -2.600 kcal for males and 1,800-2,600kcal for females. Energy intake of the subjects was higher than that of RDA. Carbohydrate, protein and fat ratio was 58 : 17: 25. The mean score of knowledge before education on diet therapy was 17.07$pm$2.02 for males, 15.19$pm$3.58 for females. The mean score of knowledge after education on diet therapy was 17.93$pm$1.33 for males , 17.31 $pm$1.49 for females.