One- to three-month-old infants (n=232) were compared their upper arm cumference and skinfold thickness(triceps, subscapular) by feeding methods in cross-sectional study. There were two groups : breast-fed(BF) and formula-fed groups(FF). As reported previously, weight, length, head and chest circumferences of these infants were good, and overall growth status was not significantly different by feeding methods, but weight, weight velocity and chest circumference of formula-fed infants were higher than breast-feds at 3month, significantly. Hear, the triceps skinfold thickness of infants at 1, 2, and 3 postpartum months were 7.4, 9.5 and 10.5 mm, respectively. The triceps skinfold thickness of breast-fed infants were higher than formula-feds at 1 and 2 postpartum month, but at 3 month that of formula-fed infants was greater than breast-fed infants, insignificantly. The subscapular skinfold thickness of infants were 6.4, 9.2 and 10.6 mm at 1 to 3 postpartum months, respectively. The upper arm circumference of infants were 11.7, 13.4, 14.3cm, and the arm muscle diameter were 34.5,39.3 and 41.7cm at one to three postpartum months, respectively. The upper arm circumference of male infants was higher than females at 2, 3 postpartum months. Overall, there were no signifiant differences between feeding methods in triceps and subscapular skinfold thickness, upper arm circumference and arm muscle diameter. But 3-month-old formula-fed male infant showed bigger significantly in arm circumference than the breast-feds. From this survey, long-term survey on growth and body composition of large scales might be necessary to determine the effect of feeding methods of infants after 3 months and to set proper body composition standard for infant.