Hydraulic fracturing developed in oil reservoir engineering has been used to improve the injection rates of reinjection wells in geothermal areas. Electrical resistivity method was designed to elucidate the fracture initiation, and then the field survey was carried out in 1980 at the Kamitakara-mura, Gifu Prefecture, Japan. Schlumberger VES station was fixed near the drill site of hydraulic fracturing well referred to as the HY well. Waveforms of induced electric current and the resulting electric potential were simultaneously monitored by 2-pen type recorder, before, during and after the stage of hydraulic fracturing operations. From an extensive series of measurements of the hydraulic fracturing processes, the following results were presented:(1) The irregular waveform of electric potentials was occurred only during the period of the hydraulic fracturing.(2) The steady linear relationship between electric currents and electric potentials was comparatively found to fluctuate directly after fracturing process.(3) Apparent resistivity of the ground by Schlumberger array decreases associated with the fracturing operation. The mechanism of the electric potential variation was considered that the streaming potentials increases because of the formation pressure by the water injected from the pump. Electrical resistivity method proved to be efficient for detecting and mapping the fluid flow in the case that the depth penetration of electrical resistivity soundings was larger than the fracturing depth.