Laobao Pb-Zn deposit in Sanjiang is the first found of Yangtze-type ore deposit in Guangxi Province. There are 11 stratiform and stratoid ore bodies occurred in interlayer structures of the Lower Sinian Laobao For- mation silieolites and the Upper Sinian Doushantuo Formation dolomites. Ore Mineral assemblage is rather simple in this deposit, which mainly are sphalerite, galena and less pyrite. Gangue minerals are mostly dolomite, quartz, calcite, barite and sericite. Country rock alterations are predominately weak silicification and carbonatization. In- tergrated with geological, fluid inclusions and stable isotopes, a genesis model of hydrothermal sedimentary min- eralization reformed by epithermal or mesothermal fluid can be constructed for this deposit. Ore metals and sulfur are mainly come from host strata and minimally from hydrothermal fluid. 0re-forming fluids probably are tectonic driven circumfluent thermal brine in the host strata.