In This paper, we studied of the landslide occurred in the northern of Iran in the southern Sari in the road of Kiasar using a physically based model has been named SHALSTAB andlandslide instability mapping of study area is determined. The Aim of This paper is to determine the Effectiveness of road construction in the landslide occurred. The model runs to base on geotechnical data extracted from laboratory testing on the 15 landslide points. A landslide inventory map along the road Kiasar, including 63 landslide points was prepared for study area. The results of field investigations, analyzing geological data, laboratory tests and running model indicated that 88% of landslides are in the unstable region which represents a successful prediction of running model in this area and also according to this model, 25/9 percent of the areas were located as stable. The results established that the SHALSTAB model is also a valuable model for prediction of landslide prone zone for the occurrence of shallow landslides in study area.