Abstract:Located in the northern part of the central segment of the Nanling Range, southeastern Hunan is a nonferrous mineralized concentration area in South China. All important deposits are related to Early Yanshanian granites, whereas a few Indosinian granites have formed large-size deposits. Studies show that the difference in tectonic settings is one of the principal factors responsible for the metallogenic differences, that is, the Early Yanshanian granites were formed in an extensional post-orogenic setting, while the Indosinian granites were formed in a weakly compressional post-collisional setting. It is also demonstrated that the Early Yanshanian granites have better W-Sn-polymetallic metalloginitic geochemical conditions than the Indosinian granites in that the former contain richer ore-forming elements W, Sn, radioactive calorific elements U, Th, and volatile elements F,Be,B, Li, Rb, are more alkaline,and have lower Fe2O3/FeO and (La/Yb)N ratios and δEu values and higher Rb/Sr ratios, which indicate that the magma has experienced a higher degree of crystallization differentiation Therefore, the petro-geochemical differences between the two kinds of granites with different ages should constitute one of the chief causes for metallogenitic differences besides the tectonic regimes. The petro-geochemi-cal differences are likely to be related to the differences in tectonic-magmatic evolution and tectonic setting.