Abstract: Through getting some yarn images of different material texture,withdrawing yarn′s brightness value using RGB color moking and HLS color mode interconversion,and made pix point positions on the yarn coordinates X,Y axis and the extracted brightness coordinate Z axis,yarn surface reflection characteristic was analyzed.From the graph,the difference of the brightness distribution of yarns with different material texture is seen.According to the yarn surface reflection characteristic,yarn surface light reflection distribution was fitted by Shepard interpolation and the lightness function was got,then yarn was simulated with the function.The yarn simulated by it looks natural and can reflect the difference of luster and the gather shape of the fiber among the yarns with different material texture.