Using about 80,000 km² of 1:200 000 regional geochemical prospecting data, the authors delineated the Ag element geochemical block in west Qinling area, studied the internal geochemical model, traced the probable places of large-superlarge type deposits. With the analogue method of metallogenic rates, the resource quantity was also predicted. The results obtained will play a guiding role in strategic ore resource prognosis and exploration arrangement of this area.