Abstract: A new method to calculate the permeability of fabric by using the fractal permeability model is introduced.This model is based on the fractal characteristics of pore in the fabric,and the permeability model can be expressed as a function of the pore area fractal dimension and architectural parameters of fabric.So it can be used to predict the permeability of fabric.Taking the plain fabric as an example,the yarn′s architectural model is improved so that the fabric′s permeability is calculated more exactly.