Abstract:ShanHu tungsten tin deposit is a large-scale quartz vein type tungsten tin polymetallic deposit in the northeast of Guangxi in the western part of Nanling metallogenic belt,tungsten and tin closely associated in most of the ores.In this paper, the cassiterite fluid inclusions in the ore of three main metallogenic stages (peritectic, mica quartz vein and quartz vein) related to tin were selected to carry out petrographic observation, microthermometry and laser Raman analysis.The results show that the homogenization temperature of pegmatite cassiterite inclusions ranges from 288℃ to 346℃, concentrated at 310℃,and salinity is 4.65%～8.95%;the homogenization temperature of mica quartz vein type is 245℃～276℃, concentrated at 270℃,and the salinity is 6.30%～8.55%; the homogenization temperature of quartz vein type is 235℃～343℃, concentrated at 250℃, and salinity is 4.65%～6.45%; generally speaking, the fluid related to tin mineralization is NaCl-H₂O with medium-high temperature and low salinity.The study shows that the temperature of ore-forming fluid is relatively high in pegmatite stage, mainly in gas-liquid phase, with low density and large fluid solubility, and its salinity distribution range is wide; with the migration and cooling of ore-forming fluid, the temperature of fluid gradually decreases, and the composition is mainly in liquid-rich phase, with the density gradually increasing and the solubility decreasing in mica quartz vein and quartz vein ore-forming stage in the middle and late stage of ore-forming,the distribution of salinity tends to be concentrated.