Laobao Pb-Zn deposit in Sanjiang, Guangxi is the first huge Yangtzi type Pb-Zn deposit that is discovered in Guangxi. The ore bodies occur in lit-par-lit structure between silicalite of Laobao group and dolomite of Doushantuo group of upper Sinian system, and they fold synchronously with strata. The mineralization is obviously controlled by the synsedimentary faults in Sanjiang, silicalite of Sinian Laobao Formation, dolomite of Sinian Doushantuo Formation, and neritic-bathyal block reducing environment.