This study analyzes the body characteristics of high school boys according to 3 different body types in order to improve the fit of upper garments. First, among the lateral body types, the straight body type was selected from the SizeKorea 3D scanned data and 2D measurement data. Second, high school boys (classified as straight lateral body type) were grouped into type B, A, and Y drop groups. The percentages of type B, type A, type Y are 17.8%, 48.1%, 32.1% respectively. The characteristics of the body types were analyzed. While the bust circumference were the same among the three body types (chest width, back width, back across shoulder, and bust width did not show a significant difference); however, waist and hip measurements showed a significant difference among the three body types. Third, the height of the high school boys ranged between 165cm and 180cm and the bust circumference between 85cm and 97cm. For the bust size categories, type B and type Y are distributed similarly; however, type A is distributed in the smaller bust size categories.