Abstract: The method of fractal geometry was used to calculate the fractal dimension of the cotton sliver thickness signal.The mumerical result indicated that the box dimension of signal data of the cotton sliver thickness is positively proportional to frequency of the irregularities of the sliver,and that the mean value of fractal dimension of widths of a certain window is propprtional to the irregularities of the cotton sliver,and that the sequence of fractal dimension of the time-series data of the cotton sliver thickness highly synchronizes with the sequence of the irregularities of the cotton sliver.Therefore the fractal dimension can be used to evaluate the evenness of the sliver.