The purpose of this study is to suggest a methodology to grasp the design method of industrial slacks pattern for women in their early twenties. The result of this study is as follows: 1. The result of the questionnaire showed that the design of rear center gradient was most important and the rear center gradient was designed by shifting waist line and hip line to a suitable degree.; below the waist by 4cm, the girth was measured and the ease of $0{sim}1cm$ was applied to it, and the ease of hip girth was $3.2{pm}1.2cm$, and rear center gradient was $2.2{pm}1cm$, and front crotch extension was $2.8{pm}0.5cm$, while rear crotch extension was $6.3{pm}0.5cm$. 2. By comparing rear center gradient which was selected as an important design item with total crotch length and hip girth, I selected industrial pattern and educational pattern, and evaluated them on human bodies. In the result of ANOVA analysis, there were meaningful differences in 8 items: the ease of front waist girth, the ease of front abdomen, the ease of front hip girth, rumples in the side lines, the location of rear waist line, etc. 3. The design method of slacks pattern suitable for women in their early twenties was suggested as follows: the location of waist girth is below waist by $2.5{sim}3cm$; the ease of waist girth is $0{sim}1cm$; the ease of hip girth is $2{sim}3cm$; total crotch length is body size - 5cm; rear center gradient is $2.5{pm}0.5cm$; rear crotch extension is $7{pm}0.5cm$; front crotch extension is 3cm.