The Shenhe barium deposit in Shaanxi Province occurs in the northern ore zone of the early Paleozoic South Qinling barium metallogenic belt. Barite and witherite are main ore minerals. Microthermometric analyses show that the homogenization temperature ranges of the fluid inclusions in barite, witherite and barytocalcite are 108~205℃ (with main peak at 130~170℃), 118~274℃ (with main peak at 150~210℃) and 146~227℃, respectively, and the salinity ranges of the fluid inclusions in the barite, witherite and barytocalcite w(NaCleq) are 0.53%~9.86%, 0.18%~8.95% and 4.03%~7.31%, respectively. The authors thus hold that thermochemical sulfate reduction transferred carbon from organic gases into witherite.