The distribution of soil particle size is one of the basic properties of soil physical properties,which has a significant effect on soil water,air and heat transfer characteristics.In this paper,five typical soil particles were analyzed by texture analysis and description of the porous structure of geomaterials.The results showed that the fractal dimension of soil increased with the increase of clay content,and decreased with the increase of sand content.The quantitative method of soil structure is to determine the fractal dimension of soil structure.For different soils,the fractal dimension of particle size distribution reflects the uniformity of particle size distribution,the larger the fractal dimension,the smaller the particle size, the higher the content of fine particles,the texture is more and more uneven.Therefore,the application of fractal theory has become a method to quantitatively describe the characteristics of soil structure.