Surface segregation in Fe-3 mass%Si (011) single crystals with residual 0.013 mass% tin was investigated by using in-situ heating in Auger electron spectroscopy. Segregation of silicon to the surface which was sputtered by argon ion took place by heating above about 700 K in the alloy. Results of the segregation kinetics showed that the segregation process is enhanced by surface damages produced by ion bombardment. It was found that at high temperatures tin is replaced with silicon on the surface. The tin segregation process was controlled by diffusion in bulk to the surface. The surface segregation of silicon and tin occurred on an overlayer, and in the tin segregation a silicon enriched zone formed below the tin overlayer. Along with characteristics for the segregation behavior, the effect of the interaction between those solutes on the segregation was discussed.