This book describes the mineralization process of barite-fluorite deposits in southeastern Sichuan, Yangtze Block, China. Mainly through systematic field geological surveys and detailed indoor research work, the typical barite-fluorite deposits in this area were analyzed using a variety of analysis methods such as single fluid inclusion LA-ICP-MS composition analysis, trace rare earth element analysis, H-O-S-Sr isotope analysis, F element content analysis, and Sm-Nd geochronological analysis. By in-depth analysis of the ore-forming environment, mineralization process and geological characteristics of barite-fluorite deposits, the following were determined: (1) the source of ore-forming fluids of barite-fluorite deposits and (2) the migration, concentration, enrichment, and evolution of ore-forming sources, exploring the formation mechanism of barite-fluorite deposits. Summarizing the mineralization regularity of the deposit in this area of China provides a new insight and basis for the study of similar types of deposits in the world.