Abstract: Machined surface topography was regarded as a stationary stochastic process, and the true surface topography was simulated by superposing series of cosine components by means of spectrum analysis. A new method was proposed to build a finite element model of surface topography. Based on linear elastic mechanics, the stress distribution induced by machined surface topography was investigated. And a concept of effective stress concentration factor was presented to reflect the total degree of stress concentration of machined surface topography. Moreover, the effect of each roughness parameter on effective stress concentration factor was analyzed. The results show that each roughness parameter of surface topography has an obvious effect on the effective stress concentration factor and there is a relation between the effective stress concentration factor and the various surface roughness parameters, which can be described with approximate quadratic equations.