The ophiolite in northeast Jiangxi is one of the most important Precambrian ophiolites in South China. Zircon U-Pb age and Hf isotope of a gabbro collected from Zhangshudun in the northeast Jiangxi ophiolite were studied for the purpose of constraining the timing and tectonic setting of the northeast Jiangxi ophiolite. LA-ICP-MS zircon U-Pb dating yielded a weighted mean ²⁰⁶Pb/²⁰⁷Pb age of 1 061±44 Ma for the Zhangshudun gabbro, indicating that the northeast Jiangxi ophiolite formed in late Mesoproterozoic. Zircon from the Zhangshudun gabbro exhibits a narrow range of initial Hf isotope ratios[εHf(t)=6.22～9.94], with corresponding t_DM1 of 1.21～1.41 Ga. The εHf(t) values are obviously lower than the value of depleted mantle reservoir (1 061 Ma) and the t_DM1 values are obviously older than the timing of zircon growth. Geochemistry and zircon Hf isotopic characteristics show that these gabbros are similar to gabbros of the typical E-MORB. These features, combined with previous research results, suggest that these rocks were mostly derived from low degree partial melting primitive mantle. It is held that the northeast Jiangxi ophiolite was formed in an initial mid-ocean ridge setting at the beginning stage of the oceanic basin spreading, and the northeast Jiangxi ophiolite is mainly MOR type ophiolite.