Abstract：In order to determine the feasibility of monitoring evolution of landslide disaster through long electrode DC survey, the resistivity variations of landslide weak contact zone monitored by long electrode and dot electrode power source were analyzed by using unstructured multi-grid FEM. Under a certain electric voltage and current conditions excited, the long electrode source could transmit more electricity to the weak contact zone and the deep stratum of the landslide. With the decrease of resistivity of landside weak zone, the potential strength of both along ground and vertical survey lines of landside increased under long electrode source. In contrast, the potential strength of the same lines decreased under dot electrode source. Under conditions of dot electrode source, there were significant abnormal potential on the depth information of the landslide weak zone along with ground survey line. However, under conditions of long electrode source, there were significant abnormal potential on the depth information with along vertical survey line. Therefore, the long power eletrode combined with the dot power electrode could effectively monitor the gestation process and weak zone position of landslide disaster.