Abstract: The building site developed along the river in Sanmenxia city of province Henan; The construction site surveyed by 2D Resistivity Tomography method. The exact locations, buried depths, water-bearing states and size of the cavities were found out, which indicate that 2D Resistivity Tomography surrey is an effectual method in practice for probing the buried cavities. If there is no water in the cavity, the anomaly would appear as a closed circle with high impedance in the 2D resistivity image. In contrast, the anomaly would manifested as a closed circle with bow impedance if there is water in the cavity.