Nutritional assessment is based on anthropometric, clinical, dietary and biochemical data. There is a lack of studies about the propriety of biochemical indexes for the nutritional assessment in children despite biochemical data in pediatric population are different from them in adult's in many respects. Serum albumin is useful index to evaluate the severity of malnutrition. Hemoglobin and hematocrit tend to decrease in malnutrition on account of defect of iron metabolism and to increase in metabolic syndrome on account of enhancement of erythropoiesis. But, unlike adult, total lymphocyte count is not so useful biochemical indexes in children. We should consider pediatric characteristic when interpret biochemical indexes for nutritional assessment in children, and nutritional status in children should be assessed comprehensively with anthropometric, clinical, dietary and biochemical data.