By making the different length and hip ease of sample shorts and using the fuzzy assessment method, the appearance and comfort of shorts and the optimum value of crotch are studied in this paper. The results show that:the length of fitting shorts is 50cm, the optimum value of crotch is 1.5cm. The length of more fitting shorts is 50cm, the optimum value of crotch is 1cm. The length of fitting shorts is 30cm, the optimum value of crotch is 2.5cm. The length of more fitting shorts is 50cm, the optimum value of crotch is 2cm. With the increase of the hip ease, the movement ease is increased and the value of the crotch is decreased. With the length decrease of trousers, the value of crotch needs to increase.