In practice of mineral exploration and engineering detection, it is typically carried out with no or incomplete prior information. For central gradient array of IP method, it is commonly the case that it is difficult to guarantee anomalous body in the middle of electrodes and that the observation data are affected and deteriorated. Therefore, it is necessary to study the electrode effect on observation data for IP method. This paper studies anomaly curve for IP method with different position between the model and supply electrodes, using experimental research method. The results provide some guidance for practical application and improve the efficiency in implementation of central gradient array of IP method.