The pore properties of the porous material are important factors influencing the vegetation to grow. The pore properties of an artificial planting material and soil were studied by a mercury intrusion test. Based on the fractal concept of Menger-sponge, the fractal dimensions characterizing pore volume-size distribution of planting material and soil are obtained from the experimental data, and the different of both of the fractal dimensions is compared. The testing results show that the total porosity of planting material varies from 30.27 % to 32.11%, and the total porosity of soil is 24.87%. The law of their pore volume-size distribution in different range of pore-size is identical. The fractal research exhibits that the fractal dimensions have a different value in all the range of pore-size for planting material or soil, and small fractal dimension corresponds to small pore-size. As compared with soil, the fractal dimension of planting material is larger slightly in range of small pore, and is same basically in range of micro and medium pore. These results indicate that the fractal dimension is a useful measure of pore grading, which divides the pore into four groups with micro pore, small pore, medium pore and large pore. And the pore properties of eco-material for erosion control of slope are helpful to the vegetation growth.