The Nibao—Baogudi Carlin- type gold orefield in southwestern Guizhou is dominated by the super-large Nibao gold deposit，as well as a series of small gold deposits and newly discovered gold occurrences. In order to investigate the nature and source of ore- forming fluids， quartz，calcite，fluorite， and stibnite closely related to mineralization were collected systematically，their geochemical characteristics of trace elements and stable isotopes were analyzed. Quartz，calcite，and fluorite are enriched in As，Sb，Li，Sr，W，in which As and Sb inherit the characteristics of ore-forming fluids. Metallogenic element Sb has good correlation with magmatic elements such as Bi，W，Mo，Co，Ni，etc.，indicating that metallogenesis is related to magmatic activity. Calcite and fluorite generally show MREE enrichment，and calcite have significant positive Eu anomalies，suggesting the ore-forming fluids is enriched in MREE and in a relatively acidic and reducing state during mineral precipitation. The δDV-SMOW，δ18OV-SMOW，and δ13CV-PDB of quartz range from -76‰ to -55.7‰ (mean value -64.9‰)，16.5‰ to 24.5‰ (mean value 21.1‰)， and -14.3‰ to -7.0‰ (mean value -10.9‰)，respectively. The δ34SV-CDT values of antimonite are -0.4‰，-0.6‰，and 1.9‰. The δ13CV-PDB and δ18OV-SMOW of calcite range from -6.5‰ to -2.5‰ (mean value -4.5‰) and 16.2‰ to 22.4‰ (mean value 18.7‰)，respectively. Comprehensive analyzed the results of C，H，O，and S isotopes from this paper and collection，indicating that the ore- forming fluid mainly originate from magmatic fluid，with the addition of part of formation water. Combined with regional geophysical and chronological data，it is believed that the mineralization of Carlin- type gold deposits in southwestern Guizhou may be closely related to the deep concealed rock mass，but has no direct genetic relationship with the basic—ultrabasic magmatic rocks exposed in the region.