This landslide is located on the road of Kyasar near the village of Takam on the Mazandaran-Damghan route. Stabilization operations were carried out in this area. However, due to the fault zone, the retaining structures again slipped. In this study, a special electrical resistivity tomography (ERT) was used to study the landslide geometry as well as to determine the level of discontinuity between sliding mass and dense bed rock. This method was performed on three profiles in the direction of perpendicular to the landslide axis. Two exploratory boreholes were drilled. The results of the research show that the main reason for the slip is the fault zone that crosses the road. In this zone, there is a severe fragmentation that drains the whole stream from the upstream and moves below the road. This in turn increases the pore pressure of the water. The presence of Marl layers exacerbates this.