This investigation presents and interprets the results of petrographic-mineralogical and thermobarogeochemical studies of ores of new gold deposit named Chertovo Koryto (North Transbaikal, Russia). Chertovo Koryto deposit is located in the north of the Patom Upland in the basin of the river Bolshoy Patom and relates to black shale type. Mineral diagnostics was conducted by using optical and X-ray spectroscopic methods. Sulfide generations are identified on the basis of typomorphic properties – crystal morphology, thermal electromotive force, microhardness, reflectivity, microelements. Determination of temperature, pressure, composition of liquid and gaseous phases of ore-forming fluids was performed by thermobarogeochemical methods, which include microthermometry, Raman spectroscopy and gas chromatography. Mineral assemblages were specificated in accordance with the detected sulfide generations, their structural correlation with other minerals and thermobarogeochemical data. Paragenetic and textural studies have established that ores of the deposit are formed by five mineral assemblages. Four types of fluid inclusions are recognized from quartz and calcite: (1) liquid-rich inclusions; (2) CO2-aqueous inclusions; (3) vapor-rich inclusions; (4) daughter mineral-bearing inclusions. The research has shown that earlier mineral assemblages (I and II) are formed within the temperature range of 400…360 °С from light-salinity fluids (6…15 wt% NaCl equiv.) of Na specialization within pressure range of 150…300 MPa. Productive Au-bearing mineral assemblages (III, IV) are formed at active participation of CO2, CH4and, partly, N within the temperature range of 350…180 °С from fluids containing Na, Mg with saltiness to 12,5…21 wt% NaCl equiv. Pressure changes within the limits of 60…200 MPa. The V mineral assemblage has been crystallized from light-salinity fluids (5…8 wt% NaCl equiv.) of sodium specialization at temperatures not exceeding 130 °С within the pressure range of 40…50 MPa. The results of this study provide an assessment of the P-T conditions and mineral-fluid evolution and suggest exploration potential for Au mineralization at Chertovo Koryto deposit.