South China is the largest and the most specific tungsten metallogenic belt in the world, Jurassic is the main ore-forming period of tungsten ore deposits in South China, and Cretaceous is the main mineralization period of tin ore deposits in China. Nevertheless, the Nanyangtian skarn-type scheelite deposit in Yunnan Province is closely linked with the Cretaceous granites in space and time and is the only skarn-type tungsten deposit discovered in Cretaceous strata. The ore-bearing rock series of the Nanyangtian skarn-type tungsten deposit comprise alternating layers composed of skarns, gneiss, granulite, schist and some other rocks, in which skarn layers are the main ore-hosting rocks and skarn scheelite is the main ore type. This paper deals with micro temperature measurement and Laser Raman spectroscopy of fluid inclusions in the Nanyangtian tungsten deposit, aimed at discriminating ore-forming fluid properties of this deposit and clarifying its ore-forming material source and metallogenic mechanism based on petrographic characteristics for the further study of the Nanyangtian skarn-type tungsten deposit. There are three dominant types of fluid inclusions related to metallogensis, as evidenced by petrographic characteristics of fluid inclusions of quartz and garnet in the Nanyangtian skarn-type tungsten deposit; they are liquid-rich inclusions, gas-rich two-phase inclusions and daughter minerals-bearing polyphase inclusions. The homogenization temperatures and salinity of fluid inclusions in quartz range from 232℃ to 337℃ and from 0.53% to 9.98 wt% NaCleqv respectively, and those of the inclusions in garnet vary from 228℃ to 306℃ and from 6.45% to 14.04 wt% NaCleqv respectively. Laser Raman spectroscopy shows that the gas composition of ore-forming fluids in Nanyangtian scheelite is mainly H2O, with a small amount of CO2, CH4, H2S, N2 and some other gases, whereas liquid composition is mainly H2O, thus suggesting a NaCl-H2O fluid system. The density of the fluids is 0.72～0.87 g/cm3. These features demonstrate that the fluids in this tungsten deposit are of medium temperature, low salinity and low density. The pressure of the fluid is 18～32 MPa, the depth of the fluid is 0.6～1.2 km, the δD values range from -72.16‰ to -65.10‰, the δ18O water values vary from 7.98‰ to 8.45‰, and the δ34S value of sulfides in the tungsten deposit is 6.6‰. These data imply that ore-forming fluids were derived from the magmatic hydrothermal process in late Yanshanian period, and magmatism caused the remobilization and enrichment of ore-forming elements to form the Nanyangtian skarn-type tungsten deposit.