The purpose of this study is for size suitability and fitness improvement for Korean 20''s women. This study has classified hip types of 20''s women by the 6th Korean Anthropometric Survey(Size Korean), then compared their lower body-type by hip types each other. The results are as follows. Factor analysis in sorting hip types can be explained 77.72% by nine factors. And cluster analysis can be divided into three types. Type 1 is referred to as a general type which has the largest size in the ''Hip circumference'', but the buttocks''s horizontal sizes are in the middle size besides the hip line. Type 2 is referred to as a protruding type in upper buttocks which is large in protruding volume of upper buttocks, but the buttock''s horizontal sizes are small including ''Hip circumference'', and buttock''s horizontal section form close to circle. Type 3 is referred to as a type which is contrary to Type 2. Type 3 is small in protruding volume of upper buttocks, but large in lower buttocks, and the protrusions in whole buttocks are small, so the side view of Type 3 made gentle fit shape. By these results, the study could classify lower body of 20''s women, and it can be basic data for new sizing systems and pattern development of bottoms.