We investigated the selenium (Se) nutrition status in Korean infants. The mean serum Se concentration in infants was 66.9 ${mu}g/L$, and it increased with increasing in infant age: 57.6 ${mu}g/L$ at 0-5 months, 71.8 ${mu}g/L$ at 6-11 months, and 75.5 ${mu}g/L$ at 12-24 months. Serum glutathione peroxidase (GPx) activity also increased with infant age. Serum Se concentration in infants was positively correlated with serum GPx activity (r = 0.565, p < 0.01). At 0-5 months, human milk-fed infants tended to have higher Se concentrations and GPx activity than those of formula-fed infants, but the result was not significant. With the introduction of supplemental feeding at 6-24 months of age, serum Se concentration was not different between the groups. Therefore, human milk feeding seemed to be more appropriate for infant Se nutrition than infant formula feeding during the first 6 months of life, but supplemental feeding became more important later to maintain good Se nutrition status.