In order to provide basic data for the means to improve food situation and nutritional status of those supported by the National Basic Livelihood Security System (NBLSS), we examined household food insecurity and nutritional status of children under the support of NBLSS. This study included 209 children aged 3-12 years (99 boys and 110 girls) and their caretakers. We measured house food insecurity using Radimer/cornell Scale, children's body sizes and nutrient intake by semi-quantitative food frequency questionnaire, and caretakers' nutritional management skills. Only 9.6% of the households were in food secured (FS) while 8.1% were in household food insecured, but without hunger (HFI), 42.1% were in adult food insecured with hunger (AFI), and 40.2% were in child hungry (CH). Important predictors of food security were nutritional management skills of the caretakers as well as their education, but neither income nor food expenditure of the households. Mean energy intake of the children was 86.0% of the Korean Recommended Dietary Allowance (RDA). Intakes of protein, phosphorous, vitamin A and B$_1$ were relatively high ranging from 112.3% to 124.4% of the RDAs while those of calcium, iron, niacin, vitamin C were low showing 74.8-83.3% of the RDAs. Height, weight and weight/height ratio were close to the reference levels. Lower nutrient intakes of children were observed as the households were more food insecured. However, nutrient intakes and body sizes of children did not differ as a function of household socioeconomic status representing by income, food expenditure and caretakers' education. Results of this study suggest the importance of food security and nutritional management skills for the children's nutrient intakes. Concerning this matter, a need for nutrition education in the program for NBLSS was discussed.