Abstarct: Because Shahrood hidden fault lies about 2 kilometer apart from north-west of Shahrood city, this fault has a vital seismological importance for this city .Therefore, in this research, a new two symmetrical pole-dipole array has been used for exploration of geometrical shape of Shahrood hidden fault. In this array, in order to increase the signal to noise ratio and the depth of exploration, with increasing the distance of current electrode, also distance of potential electrodes must be increased simultaneously relative to the center of array. After processing and modeling of data, geometrical shape of the hidden fault, has been determinate.