Abstract: The present paper gives a detailed description of the application of GIS-based weights of evidence method to the evaluation of the copper polymetallic ore deposits in the northern part of the Nujiang-Lancangjiang-Jinshajiang area, Qinghai. Seven forecast prospects have been delineated by using GIS techniques on the basis of the geological data including geophysics, geochemistry and mineral resources database, and then the GIS-based weights of evidence modeling has been constructed. The results of research will provide a scientific basis for the further exploration and development of the mineral resources in the study area.