Landslide occurred in the newly-built school in the Zirab city of Mazandaran province. The construction of this area was carried out in hilly terrain with a relatively steep slope. Most of these structures are faced with the problem of landslide and incurred a lot of damage. The landslide has caused numerous cracks and fractures in the school building. According to the importance of the structure, electrical resistivity tomography (ERT) was performed using two-dimensional tomography with bipolar-bipolar arrangement and vertical electrical sounding (VES). Also, three geotechnical boreholes were drilled. Combining the results of ERT, VES and exploratory boreholes shows that there is a water flow path in the subsurface layer and at a depth of 4 to 5 meters, which weakens the layers and creates a slip. With landscaping and directing the flow of water, landslide can be largely stabilized.