Abstract: The Jinjishan manganese deposit in Hanpoao，Xinhua County，Hunan Province is a repre⁃ sentative oxidized manganese deposit. To better develop the Jinjishan manganese deposit the genesis and mineralization potential of the deposit were explored，the geological characteristics of the manganese depos⁃ it were analyzed and summarized，field geological surveys were conducted，and representative samples were collected in the tunnels. Combined with the geological characteristics of the deposit，the research fo⁃ cused on the study of trace elements in manganese ores and the state of manganese distribution. In the re⁃ search，the content of Mn was determined by ferrous sulfate titration，the content of Fe was titrated with potassium dichromate standard solution，the contents of other trace elements were analyzed by inductively coupled plasma emission spectrometer (ICP-OES)，and X-ray powder diffraction (XRD) was used to ana⁃ lyze the phase of manganese. The study showed that the ratio of Fe/Mn in the manganese ore was 0.06~ 0.98，which was lower than that of the surrounding rocks. The manganese ore was enriched in K，Ca，Mg， Co，Ni，etc. The Co/Zn value of the Hanpoao manganese deposit was 0.06~0.98，indicating that the man⁃ ganese ore might originate from hot water deposition. The Fe-Mn-(Co + Ni + Cu) × 10 and Co/Zn-Co + Ni + Cu diagrams indicated that the formation of the manganese ore might be the combined result of chemical precipitation after the mixing of hot water deposition and cold seawater. The XRD analysis results showed that manganese was present in the manganese ore in the form of Pyrolusite. Based on all the test results， the geological characteristics of the manganese deposit were studied. The deposit was formed first by hot water deposition and cold seawater mixing through chemical precipitation，resulting in manganese-bearing limestone and manganese-rich argillaceous siliceous rock. Then，it was formed through weathering，sedi⁃ mentation and secondary enrichment. The formation of the ore body was closely related to the oxidation pro⁃ cess. The deeper the weathering degree，the higher the manganese grade. The distribution areas of manga⁃ nese-bearing limestone and argillaceous siliceous rock in the areas near faults were the main favorable ar⁃ eas for prospecting.

Key words: manganese deposit, geological characteristics, trace elements, mineral phase