Abstract: East Tianshan is a crucial mineral resource base in China,yet silver-dominant deposits are rarely reported.Baishidu Silver Deposit,the first hydrothermal-vein type silver deposit reported in this region,is also the first independent silver deposit discovered.The host rocks are predominantly Late Carboniferous to Early Permian reddish porphyritic monzogranite and greyish-green dioritic dikes.The primary ore body is lens-shaped,trending northeast and extending about 250 m,with silver grades of 48.5×10-6 to 60.3×10-6 and lead grades of 5.24 % to 9.90 %.The δ34S values of galena range from 3.8 ‰ to 6.3 ‰,averaging 5.01 ‰,while quartz δ18O values vary between -8.3 ‰ and -5.0 ‰,averaging -6.30 ‰.The study suggests that Baishidu Silver Deposit is a hydrothermal-vein type,distinct from other sedimentary-transformed or stratabound hydrothermal silver deposits in the region.Mineralizing fluids are a mix of magmatic water and meteoric water,with the mineralizing materials deriving from both crustal and mantle sources.There is potential for discovering porphyry-type molybdenum deposits related to the same mineralization system near the base of this deposit.