The aim of this study is to develop clothing size system according to each size interval for obese girls aged 10~12 by classifying the upper bodies. The criteria for subjects in this study were girls who had over 1.46 of the R$ddot{o}$hrer Index. A total of 229 schoolgirls who met these criteria were enrolled. Results are as follows; 1st, 5 factors were extracted by factor analysis and 3 clusters were categorized by cluster analysis, cylinder-type, inverted triangle-type and inverted trapezoid-type. And 2nd, as a consequence of size system establishment, the basic body sizes and reference body sizes were different according to types even in commonly-appeared size names at sections of respective types. The research findings above suggest that it is necessary to figure out the obesity types according to height and bust girth sizes representing basic sizes and to design the patterns in consideration of the characteristics of obese body shapes. And it may be used as a basic data to decide the desirable output of production according to respective body types.