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 orebody 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 strata-bound 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.