To explore the evolution of oceanic redox state during the Terreneuvian Epoch, South China, total organic carbon (TOC), iron speciation, sulfur isotopic composition of pyrite and kerogen and carbon isotopic compositions of kerogen were analyzed on the Zhalagou section, Guizhou Province. The studied section was deposited in an isolated palaeotopographic high under the slope basinal background. On the basis of combined tools for stratigraphic correlation, including redox sensitive metal elements (such as Mo, U, V and Ni) ,sulfide , and organic matter rich horizon, the chert units, phosphate bearing layer, and organic carbon isotope in kerogen, the analyzed intervals in the Zhalagou section were time equivalent with the lower to middle parts of Shiyantou Formation. The high FeHR/FeT ratio (reactive iron to total iron: > 0.38), and low Fepy/FeHR ratio (pyrite iron to high reactive iron: <0.6) indicate that the Laobao Formation were deposited under anoxic, non sulfidic environment. Conversely, the high FeHR/FeT ratio (> 0.38), and high Fepy/FeHR ratio (mostly >0.7) indicate that the major parts of overlying Zhalagou Formation were deposited under anoxic and sulfidic environment and that the rests were deposited under transient anoxic, non sulfidic environment. The more enriched values of δ34Spy and δ34Skero in the Laobao Formation demonstrate that the bottom water was under anoxic and non sulfidic conditions, and that bacterial sulfate reduction mainly occurred in the relatively closed pore waters. The more depleted values of δ34Spy and δ34Skero in the sulfidic intervals of Zhalagou Formation, demonstrate that H2S accumulated into the bottom seawater, and that bacterial sulfate reduction proceeded under an open system with a larger fractionation.