Slope　structures　are　commonly　used　in　buildings,　but　such　slope　structures　can　exacerbate　the　rate　of　fire　spread,　complicate　building　fire　safety　and　suppression,　and　lead　to　injuries,　deaths,　and　property　damage.　Particularly,　the　thermal　hazards　posed　by　ambient　wind　on　sloped　fires　remain　unquantified.　In　this　study,　a　propane　burner　was　used　to　simulate　the　flame　morphology　behavior　of　a　sloped　building　fire.　480　tests　were　conducted　with　varying　aspect　ratios　(1∼8)　of　the　fire　source,　different　ambient　winds　(0　m/s∼3.5　m/s),　and　slope　inclination　angles　(0°∼40°).　Results　demonstrate　that　the　flame　length　initially　increases　and　then　decreases　with　an　increment　in　ambient　wind　velocity.　Moreover,　with　an　increased　aspect　ratio　of　the　fire　source　(length-to-width　ratio),　the　turning　point　at　which　the　flame　length　peaks　shift　to　occur　at　a　lower　wind　velocity　threshold.　The　tilt　angle　and　height　of　the　flame　change　(respectively　increases　and　decreases)　significantly　at　lower　ambient　wind　speeds　and　they　tend　to　asymptotically　approach　respective　constant　values.　As　the　ambient　wind　is　further　promoted.　Existing　physical　models　of　flame　morphology　do　not　consider　the　combined　effects　of　fire　source　aspect　ratio,　slope　inclination　angle,　and　ambient　wind.　A　new　slope　entrainment　restriction　factor　(EF)　was　proposed　based　on　an　analysis　of　the　upward　and　leeward　entrainment　volumes.　Using　this　factor,　new　models　for　flame　morphology　(including　flame　length,　flame　tilt　angle,　and　flame　height)　were　established.　The　accuracy　and　generalizability　of　the　new　flame　models　have　been　validated　using　reference　data.　©　2024　Elsevier　Ltd