Abstract: A method for knitting denim comprising: dyeing yarn with a dyestuff to obtain dyed-yarn; knitting the dyed-yarn into a foundation layer and front layer to compose the denim, wherein the front layer is tensely tautened in intermittence with a tensile force greater than a tensile force on the foundation layer to make the foundation layer have random knots; and respectively washing two faces of the denim to remove the residual dyestuff. By knitting the yarn to compose the denim, the denim has even twilling patterns and excellent softness. By tensely tautening the front layer in intermittence during the knitting process, multiple random knots are generated on the foundation layer. Therefore, the achieved denim possesses multiple good features of softness, random knotting, and even twilling patterns.