Volcanic edifice of Linzizong Group in the Nanmulin basin of Lhasa Block host the Sinongduo cryptoexplosive brecciastype and hydrothermal veintype AgPbZn deposit. The deposit consists mainly of sphalerite and galena, with minor amount of chalcopyrite and argentite. Altered minerals are sericite, illite, chalcedony, montmorillonite, jasper, calcite, rhodochrosite and siderite, which are consistent to the basic feature of lowsulfidation epithermal deposit. This study carried out the Si, H and O isotopic analysis of siliceous bands and quartz veins cutting orebodies in vents of terrigenous volcanic rock. The results show that (1) the single mineral quartz in the siliceous bands has δ30SiNBS28 of -1.2‰~-0.4‰, which 〖JP3〗records geochemical features of hydrothermal sedimentary Si isotope, suggesting a sinter genesis of ancient hot spring. (2) Whole rock analysis of hydrothermal sedimentary siliceous bands reformed by late volcanic hydrothermal process has 30SiNBS28of -0.2‰~+0.3‰，indicating a mixing feature of volcanic rock and hydrothermal sedimentary rock. (3) Quartz veins cutting through orebodies have δ30Si NBS28value of -0.8‰~-0.1‰, which is consistent to that of mineral quartz in hydrothermal sedimentary siliceous bands, showing high Δ30Si feature of low temperature origin. (4) O and H isotopic features of fluid inclusions from quartz veins and siliceous bands suggest O isotopic shifting due to waterrock reaction between meteoric water and volcanic rocks, indicating that oreforming fluids experienced longterm recycling within volcanic rocks strata. Therefore, SiHO stable isotopic values indicate the existence of ancient hot spring in the mining area. This study shows that despite the low degree of denudation in this area, there are still great potential for lowsulfidation epithermal AuAg type deposits, with quartz veins of low δ30SiNBS28 and silicification being the important indicators for exploring lowsulfidation epithermal AuAg type deposits.