The Ediacaran trace elements and Fe isotopes of the black shales of the Doushantuo Formation from the Jiulongwan section in the Three Gorges area have been used to contrain redox conditions of the Ediacaran ocean. The enrichment factor of redox sensitive element and U/Th, V/(V+Ni), V/Cr values of the black shales exist obvious evolutional trend during the Ediacaran period, which show the ocean of the lower of the Doushantuo Member Ⅱ was in an oxic condition, the ocean of the upper of the Doushantuo Member Ⅱ was in a reduced state, and the black shales of the Doushantuo Member Ⅳ deposited in an oxic environment. Meanwhile, the black shales in the lower of the Doushantuo Member Ⅱ are enriched in heavy isotope, which demonstrates that iron from seawater is mainly controlled by the Fe 3+ minerals, and further illustrates that the ocean was in oxidized state. Comprehensive on trace elements and Fe isotopes show the ocean experienced first oxidation then reduction process during the early Ediacaran, and was in a relatively oxidizing environment during the late Ediacaran (Doushantuo Member Ⅳ) This feature is corresponding to evolution of biota during the Ediacaran period, impying that the oxidation of ocean could create prerequisite conditions for the emergence and evolution of multicellular metazoans.