The Ashele copper zinc deposit that is under exploration in Habahe County, Xinjiang, is of marine volcanic exhalation-sedimentary origin. Thick, large and lenticular orebodies exhibit the stratabound charater, and there is appreciable difference in density between orebodies and country rocks. In order to have a better understanding of the structural setting of the ore district and study and gain the information and indications of mineral prospecting at depths, the method of mathematic geology-orthogonal function fitting-and the quandratic fitting technique were used in processing the geological infromation about the morphological features in space. The local gravity anomalies due to the ore horizons were separated from the measured Bouguer anomalies according to the results of the processing. Thus three N-S-trending gravity high anomaly belts , structural turning zones and the N-W- and E-W-trending fracture structures, which are not easy to observe on the ground surface, are clearly displayed on the processed local gravity anomaly contour map. On that basis, the authors have outlined successfully a tectono-metallogenic belt, unveiled the structures in the ore district and pointed to the direction in ore prospecting.