The　Jilongshan　Au-Cu　skarn　deposit　is　located　at　the　Jiurui　ore　district　of　the　Middle-Lower　Yangtze　River　metallogenic　belt　(MLYB),　which　is　a　significant　metallogenic　belt　for　dispersed　elements.　The　Jilongshan　deposit　hosts　abundant　critical　metal　elements　(e.g.,　Se,　Te,　and　Bi)　and　shows　potential　for　the　comprehensive　utilization　of　these　critical　mineral　resources.　This　study　examines　the　mineralogical　textures　and　compositions　of　sulfides　and　sulfosalts　from　the　Jilongshan　deposit　through　EPMA,　TIMA,　and　LA-ICP-MS　analyses　to　clarify　the　nature　of　the　occurrence　and　distribution　of　Se　and　Te.　Based　on　the　host　rocks,　the　ores　can　be　divided　into　porphyry-hosted,　marble-hosted,　and　skarn-hosted　types.　Selenium　content　is　significantly　higher　in　porphyry-hosted　and　skarn-hosted　ores　compared　to　marble-hosted　ore,　while　Te　is　most　abundant　in　marble-hosted　ore.　Apart　from　rare　minerals　such　as　clausthalite　(PbSe),　hessite　(Ag2Te),　and　hedleyite　(Bi7Te3),　Se　and　Te　predominantly　occur　as　isomorphism　within　pyrite　(∼70　%)　and　tetrahedrite　(∼20　%).　On　the　basis　of　mineral　assemblages　and　textures,　tetrahedrite　can　be　recognized　as　three　generations,　including　Ttr1　(replacing　Fe-Cu　sulfides),　Ttr2　(intergrown　with　Pb-Zn　sulfides),　and　Ttr3　(replacement　of　last　pyrite).　Selenium　is　enriched　in　minerals　precipitated　in　the　Fe-Cu　stage,　including　hydrothermal　pyrite,　chalcopyrite,　and　Ttr1,　with　the　average　of　345　ppm,　183　ppm,　and　592　ppm,　respectively,　while　Te　mainly　concentrates　in　minerals　formed　in　the　Pb-Zn　stage,　such　as　galena　(143　ppm),　Ttr2　(3112　ppm),　and　Ttr3　(489　ppm).　These　findings　align　with　previous　studies　on　the　Se-Te　relationship　and　may　indicate　that　Se　is　more　likely　to　be　enriched　at　a　higher　temperature,　while　Te　exhibits　the　opposite　trend.　The　variation　in　sulfur　fugacity　within　fluid　systems　may　also　play　a　role　in　the　enrichment　of　these　critical　elements.　Additionally,　the　regional　distribution　and　enrichment　of　Se　and　Te　in　the　porphyry-skarn　deposits　of　the　MLYB　also　shows　certain　regularity.　Selenium　is　more　likely　to　be　enriched　in　high-temperature　porphyry　ores,　while　Te　is　most　abundant　in　relatively　low-temperature　interlayer　ores.　©　2024　The　Author(s)