Abstract: Hornfels has become one of the most important host rocks in the Jiama copper polymetallic deposit since the drilling exploration exposed it more in recent years. The molybdenum and copper resources hosted in hornfels have assessed to reach the large scale, so it will provide more resources for the mine as a new ore type besides skarn type and porphyry type ore in Jiama. However, study on hornfels in Jiama is at the very low level, especially on its significance on deep prospecting. Hornfels feature in Jiama has been studied including analysis on its space distribution, mineral assemblage, chemical component and statistic on fracture in hornfels. Based on the above feature, the speculation on the center location of deep rock body and suggestion on deep prospecting have been discussed. Hornfels in Jiama spreads widely with uneven thickness. In drillhole ZK3218, it reaches 1027m thick, and hornfels trends to less thick in the surrounding and thins out in some drillholes in the southwest end and west end. Molybdenite and chalcopyrite are the main ore mineral in hornfels with wide scope but lower grade than skarn. The hornfels type orebody in drillhole ZK3217 reaches 900m thick locating closely to ZK3218. The statistic on fractures in hornfels has showed the concentrated area circled the drillhole ZK1616-ZK3216 with more than 40 fractures in each meter and gets less in around. Combined with the above feature of hornfels, it’s suggested to arrange the deep drilling in the area of ZK3216-ZK3217-ZK3218 which is supposed to be the heat center for hornfels, and the deep drilling may hit the skarn type orebody and porphyry type orebody.