Abstract: The Gemalong Ag polymetallic deposit located in the East Kunlun metallogenic belt, Qinghai Province. Eight ore-bearing alteration zones and 27 Ag polymetallic orebodies have been identified in the Gemalong mining area. The estimated resources of Ag, Au, and Pb+Zn are 320.4 t, 0.5 t, and 1229.47 t, respectively. There is a geomagnetic anomaly M1 (1∶10,000) in the southeast mining area, and the ore-bearing alteration zones have been found in a circular distribution around M1 magnetic anomaly. However, the relationship between M1 magnetic anomaly and mineralization has not been paid attention to. This time through the magnetic method, IP, controllable source sounding and other geophysical methods used, based on the analysis of surface and vertical elements, mineralization and alteration zoning,think that M1 magnetic anomaly is caused by sulfides from granodiorite porphyry, which is the metals and fluids sources of epithermal mineralization in this area. The M1 magnetic anomaly is similar to the magnetic anomaly caused by porphyry deposits, which suggests the potential for porphyry mineralization.