The Youjiang Basin, located in the southwest margin of the Yangtze blocks, is an important part of the large-area low-temperature metallogenic domain in China, and the metal sources and enrichment processes of the low-temperature Au、Sb and Hg deposits in the basin still need to be clarified.Prebious studies have shown that the Lower Cambrian black shale series are enriched with low-temperature metallogenic elements (such as As,Sb,Au), which may provide a material basis for low-temperature metallogenic in the Youjiang Basin.In order to further reveal the relationship between the Cambrian polymetallic black shale series and the low-temperature mineralizationin in Youjiang basin,in this paper,elemental geochemistry, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in-situ trace elements and fluid inclusions were carried out on the Lower Cambrian (Niutitang Formation and Gezhongwu Formation) black shale (phosphorus-bearing rock formations) and their later hydrothermal veins.The results showed that: 1)The content of Sb and As in this Lower Cambrian strata was higher than that in the upper crust(enrichment coefficient was 2~69).The lg(U)-lg(Th) relationship diagram shows that the enrichment of Sb-As in the hydrothermal vein-bearing phosphoblock rocks of the Lower Cambrian Gezhongwu Formation is mainly affected by hot water (liquid).2)The temperature of the later hydrothermal quartz vein fluid inclusions was concentrated in the range of 137.4~260℃, and the salinity was 0.18~5.11wt% NaCl equiv, which was basically the same as that of the low-temperature ore-forming fluid in Youjiang basin (140~270℃, 1.5~7.0 wt% NaCl equiv).3) Two types of apatite are developed in the hydrothermal vein-bearing phosphobolite rocks, which are sedimentary apatite (Fap1) and hydrothermal apatite (Fap2). Among them, Fap1 has a typical bioclastic structure, and Fap2 has a flat surface and is mainly developed near the late hydrothermal quartz veins. Electron probe (EPMA) and LA-ICP-MS analysis showed that compared with Fap1, Fap2 was more enriched in low-temperature elements such as Sb, As and Cu, and depleted rare earth elements.Based on the above analysis, this paper considers Fap1 to be a typical biosedimentary apatite, which is the main carrier of rare earth elements in phosphorites. Fap2 is a hydrothermal apatite formed in the later period, which is obviously enriched in low-temperature mineralizing elements (Sb, Cu, As).The lower content of low-temperature mineralizing elements (Sb, Cu, As) in Fap1 reveals that the Lower Cambrian strata are not sufficient to provide a material basis for low-temperature mineralization, and on the contrary,the late hydrothermal fluids (such as Carlin-type mineralizing fluids) originating from deep (such as metamorphic basement or magma) may be one of the reasons for the abnormal enrichment of low-temperature mineralizing elements in the Lower Cambrian black shales.