To propose a basic material that can improve the crumples in the knee area and can be applied as an element of garment design, the present study examined the elongation rates of the samples by differentiating the number of cutting lines according to the direction of the fabric, and then determined the puckering phenomenon by judging the conditions of the seams based on the looks of seam lines after bi-axil elongation. After the subjective evaluation on the knee areas of both the standard and modified trousers, the following conclusion was drawn : The elongation rates of the samples are: warp (3.98%)<warp1 (4.29%)<weft1 (5.30%)<weft (5.82%)<warp2 (5.68%)<bias (6.96%)<weft2 (8.64%). The samples in the warp direction: as the cutting lines increase, the elongation rate grows by 1.4%. The elongation rates of the samples in the weft direction: the sample with one cutting line has 0.52% lower rate than that in the weft direction without cutting line; that with two cutting lines has 1.68% higher rate than that running on the bias. The subjective evaluation on the knee areas: the subjects wearing the standard trousers feel more comfortable when sitting on a chair (0.2)>cross-legged (-0.2)>squatting down (-0.4); those in the modified trousers feel more comfortable when sitting on a chair (0.2)>cross-legged (0)>squatting down (-0.6). In the cross-legged posture, the modified trousers (0) has higher scores in the subjective evaluation than the standard ones (-0.2). The evaluation on the looks of needleworks in the samples with cutting lines along the direction of the fabric: weft2 (5.0)<weft1 (4.8)<warp1 (3.8)<warp2 (2.8).