Abstract: In this paper, the method for fractal description of soil grains is improved and applied to describe the grain composition charateristic of interlayer shear zones. According to the fractal charalteristics, the grains from interlayer shear zones are classified into five types. Based on this result, their engineering geological indications are extensively and intensively discussed. A much attention is paid to amplitude of displacement and development stages of grains in the interlayer shear zones and their identifications by means of fractal character istics. And many aspects to be further discussed are also given.