In the present paper basin fluids refer to extremely complex aqueous solutions which are very active in all the diagenetic-epigenetic processes of sediments during the evolution of sedimentary basins. They mainly include fluids produced by compaction and phase change of sedimenu inside the basin as well as meteoric water driven downwards into the sedimentary basin by the gravitational potential along uplifting continental marlins adjoining the basin. Pasin fluids show typical features of low-temperature hydrothermal geochemistry, with temperatures mainly ranging 80-150℃. Isotope composition and dissolved compositions of basin fluids are controlled by sediment types decided by fluid-mineral interactions) and their spatial distribulion .The contribution of organic matters plays a very impotant role in such aspects as the fluidmineral interaction the change in physical-chemical parameters of basin fluids themselves and their environments the dissolution transport deposition and ore-forming process of metals and the formation of secondary porosity of sedimentary rocks. Pasin fluids make a very important contribution to dia}enetic-epigenetic processes of sediments, oil-has production and ore-formation in sedimentary basins. Spatial distribution of sediment systems together with syndepositional faulting systems uncompacted overpressure systerns and paleotopography of sedimentary basins controlled the migration and accumulation of basin fluids and the metals carried in the fluids. Ore deposits genetically related to basin fluids can be classified into four groups, viz. sedex type deposits MVT lead-zinc deposits continental sandstone type deposits and sediment-hosted micro-disseminated fold deposits. Two examples of deposits in China formed by basin fluids one belonging to sedex the other to sediment-hosted micro-disseminated fold deposit，are beiefly discussed in this paper.