We study Si adatom diffusion process near Si/Ge stepped surfaces from first-principles. Dependence of surface growth morphology on growing conditions such as temperature is not clearly understood. We calculate Ehrlich-Schwoebel(ES) barrier of stepped surfaces from first-principles and analyze adatom diffusion process to understand growth mechanism of the surfaces. The configuration of the surfaces with ES barrier would play a key role in the diffusion process because it controls hopping rates in the presence of step edges. Our results are likely to help correctly access the adatom diffusion process on the surfaces.