With the direct access technique of a column or a block of grid data, it is possible for us to calculate the total gradient amplitude and to search automatically and trace continuously the maximum points of grid data in large quantities. In this paper, the authors put forward for the first time the idea of continuous tracing of a string of adjoining maximum points along the anomaly trend after automatic searching of a maximum point. The linking lines of the string of maximum points can show the horizontal sites of edges (or centers) of magnetic or gravity bodies and structures more directly and effectively. The practically improved software was used in inversion of model and surveying data, with fairly good results obtained.