lourmaime is a complex borosihcate mineral which occurs in many granites, pegmatites, metamorphic and sedimentary rocks and in a variety of hydrothermal ore deposits, especially some massive sulfide deposits, mesothermal Au-Ag and Sn-W deposits. There is a wide variation in chemical compositions of tourmaline from various geological settings, which typically reflect the environments in which tourmaline is crystallized. A large range of trace elements including Cu, Pb, Zn, Ag, Sn, Cr, V, Sr and REE are documented in tourmaline as minor or trace constituents. Their concentration levels and distribution patterns record their paragenetic conditions and are good indicators for petrogenesis, minerogenesis, and miheral prospecting. Stable isotopes of O, H, B and Si in tourmaline are suggested to be good tracers for hydrothermal fluids, fluid -rock interaction and the origin of rocks and ore deposits, and can provide valuable information regarding temperatures of tourmaline formation. The Rb-Sr and Sm-Nd isotopic compositions of tourmaline have major implications for source reservoirs and the nature of hydrothermal fluids, and can yield geological meaningful ages for tourmaline formation and related mineralization. Pb-Pb isotope studies of tourmaline obtained by stepwise Pb leaching techniques have been proven to be a good geochronometer, and K-Ar, 40Ar-39Ar systematics of tourmaline may also be useful for age determinations. Therefore, tourmaline has been used as a sensitive tracer for rock-forming and ore-forming processes, and for tourmalinization dating and associated hydrothermal alteration , mineralization, and metamorphism.