The methodology of applying fabric stretch ratio in the grants pattern drafting was evaluated. The experimental fabrics employed in this study were 3 different knit fabrics with various stretch ratio in vertical or horizontal direction. The firm fitting pants pattern was modified by applying the fabric stretch ratio in vertical ana horizontal direction. The computer automatic drafting method was used for pants pattenl alteration. The suitability of the altered pattern was evaluated by the 7 clothing specialists, The results showed that fit of all experimental garments was improved in general. The garment which was constructed with the fabric having large difference between horizontal stretch ratio and vertical stretch ratio showed poor fit at crotch area. This result implies that computer aided pattern alteration is not appropriate when fabric stretch ratio is vary by the fabric directions.