Abstract: The Yingchengzi gold deposit, located in the east margin of the Xingan-Mongolia orogenic belt, occurs in the E-W-trending of mylonite zone, with ore bodies in veins and lenticular forms. The assemblages of ore minerals are pyrite, chalcopyrite and sphalerite, with metasomatic, dropwise and subhedral-anhedral textures and disseminated, veined and banded structures. The mineralization can be divided into four stages, namely, quartz-arsenopyrite-pyrite stage, quartzpyrite stage, quartz-polymetal sulfide stage and quartz-calcite stage. The ore-forming fluids belong to CO₂-CH₄-H₂O type characterized by moderate temperature, low salinity and low density. The Yingchengzi gold deposit shares some common characteristics with the typical orogenic gold deposits from both China and overseas. Its genesis may be assigned to orogenic type of gold deposit.