[en] Underground hydrology is one of important items for the assessment of the high-level radioactive waste disposal. Rock fractures play an important role in local hydrology in fractured rock mass. In order to develop the technique of rock fracture survey, basic study on resistivity tomography has been carried out using an experimental tank 2x2m square and 2.2m in depth. The tank was filled with a NaCl solution to represent a homogeneous geologic media. A multi-electrode representing electrodes that will be arranged in field was used in the tank for a physical model simulation with 4 different sized fracture models. The detection limit of the resistivity tomography using a pole-pole array was discussed based on the results of both the physical and numerical model simulations. (author) 60 refs