Abstract: Baguamiao gold deposit locates in the Devonian low-grade metamorphic rocks. According to a study on fluid inclusions in quartz from the main mineralizing stages, it was found that the ore-forming fluid was of salinity, from low, middle to high salinity (with daughter minerals). Pyrite and salt were identified among these daughter minerals by SEM/EDS and EPMA, LRM was also used for checking the composition of fluid inclusions. All of fluid inclusions was detected to be rich in CO₂ and CO, SO₂, CH₄, H₂S, and C₂H₂. C₂H₄ was also detected in some of them. It is concluded that the ore-forming fluid is of more reducing and complicated physical-chemical conditions.