Abstract：Geochemical methods have been commonly used in the quantification of mineral resources. Most of these methods, however, are based merely on geochemical data, with less attention paid to geological factors such as tectonics and strata. In consequence, the estimation of mineral resources frequently fails to conform to the reality. Based on a study of geological factors, the authors consider material basis and enrichment intensity as important metallogenic conditions and have thus established a new areal productivity based on the probability of mineral occurrence by modifying the traditional areal productivity. To some extent, this method wipes off pseudo-estimation. The authors calculated the copper potential resources of copper-nickel sulfide deposits in East Tianshan Mountains and obtained satisfactory result. It is shown that the potential of copper resources in the East Tianshan Mountains is very great.