In the current, natural resources are utilized extensively such as minerals, petroleum and underground water sources. Geophysical survey is very important to exploration geological structure or exploring the natural resources. The purpose of the geophysical survey are knowing the geological features and physical properties (i.e. density, magnetization, elasticity and electric conductivity, etc. ) at the area that is interesting. These data can be used for planning to well drilling in the area to explore them even more effective. Survey of geological structure, there are many ways. For instance gravitational, magnetic, seismic, electrical, electromagnetic, radioactivity, etc. The magnetic method is the widely used method by the device is electrodes (source) and receiver which is installed on the ground.The working principle is that when we leave the DC voltage to the electrode will cause a magnetic field. When the magnetic field is moving through the medium. They are medium induction to produce magnetic field, which can be measured with receiver. We have information on magnetic fields in the area of the survey, these data can be interpreted show the basic information of the various physical properties of the target.