随着测量分辨率的提高，工程粗糙表面会有无穷细致的结构产生，所以，任何传统的对粗糙表面定量的描述，都随测量尺度的改变而变化，未能触及到表面形貌的本质性质．文中将分形几何学用于表面微观形貌的研究，明确给出了有关分形参数的物理意义，并基于Ｗ－Ｍ函数建立了分形参数与传统表面精度指标间的关系，为粗糙表面进一步的分形研究打下了基础． As measurement resolution increases, there are infinitely detailed structures in the rough surface of the project. Therefore, any traditional description of the roughness surface varies with the measurement scale and fails to reach the essential nature of the surface topography . In this paper, the fractal geometry is used to study the microstructure of the surface. The physical meaning of the fractal parameters is clearly given. Based on the W-M function, the relationship between the fractal parameters and the traditional surface accuracy index is established. Research laid the foundation.