Triple-negative　breast　cancer　(TNBC)　is　an　aggressive　subtype　of　mammary　carcinoma　characterized　by　low　expression　levels　of　estrogen　receptor　(ER),　progesterone　receptor　(PR),　and　human　epidermal　growth　factor　receptor　2　(HER2).　Along　with　the　rapid　development　of　the　single-cell　RNA-sequencing　(scRNA-seq)　technology,　the　heterogeneity　within　the　tumor　microenvironment　(TME)　could　be　studied　at　a　higher　resolution　level,　facilitating　an　exploration　of　the　mechanisms　leading　to　poor　prognosis　during　tumor　progression.　In　previous　studies,　hypoxia　was　considered　as　an　intrinsic　characteristic　of　TME　in　solid　tumors,　which　would　activate　downstream　signaling　pathways　associated　with　angiogenesis　and　metastasis.　Moreover,　hypoxia-related　genes　(HRGs)　based　risk　score　models　demonstrated　nice　performance　in　predicting　the　prognosis　of　TNBC　patients.　However,　it　is　essential　to　further　investigate　the　heterogeneity　within　hypoxic　TME,　such　as　intercellular　communications.　In　the　present　study,　utilizing　single-sample　Gene　Set　Enrichment　Analysis　(ssGSEA)　and　cell-cell　communication　analysis　on　the　scRNA-seq　data　retrieved　from　Gene　Expression　Omnibus　(GEO)　database　with　accession　number　GSM4476488,　we　identified　four　tumor　subpopulations　with　diverse　functions,　particularly　a　hypoxia-related　one.　Furthermore,　results　of　cell-cell　communication　analysis　revealed　the　dominant　role　of　the　hypoxic　tumor　subpopulation　in　angiogenesis-and　metastasis-related　signaling　pathways　as　a　signal　sender.　Consequently,　regard　the　TNBC　cohorts　acquired　from　The　Cancer　Genome　Atlas　(TCGA)　and　GEO　as　train　set　and　test　set　respectively,　we　constructed　a　risk　score　model　with　reliable　capacity　for　the　prediction　of　overall　survival　(OS),　where　ARTN　and　L1CAM　were　identified　as　risk　factors　promoting　angiogenesis　and　metastasis　of　tumors.The　expression　of　ARTN　and　L1CAM　were　further　analyzed　through　tumor　immune　estimation　resource　(TIMER)　platform.　In　conclusion,　these　two　marker　genes　of　the　hypoxic　tumor　subpopulation　played　vital　roles　in　tumor　development,　indicating　poor　prognosis　in　TNBC　patients.