The purpose of this study was to offer a more functional slacks by analyzing its crotch length. The result of the study were as follows : Regarding the feeling of wearing and appearance, the P2 b style which measures the crotch length starting from the waist line passing around the iliac spine was the most highly evaluated. This suggested that the functionality of dance movement was more influenced by the position of the waist line not by the crotch length measurement. Since the front and rear center lines of the crotch could not be flown if the waist line of slacks was positioned high, both the crotch and abdominal part might be clogged or tightened when dancers made large dance movements or bended their upper bodies forward. In conclusion, slacks for more functional dance movement should be manufactured focusing on the location of the waist line rather than on the crotch length.