Multiple　fires　of　unequal　heat　release　rate　(HRR)　is　a　common　fire　scenario　in　real　fire　accidents.　Differing　from　most　previous　research　assumption　of　identical　fire　sources,　the　unequal　HRR　for　those　fire　sources　is　regarded　as　more　reasonable　in　reality.　To　explore　the　asymmetric　flow　characteristics　surrounding　multiple　fires　under　such　circumstances,　simulations　of　two　square　propane　burners　with　the　same　side　length　but　different　HRRs　were　carried　out.　The　HRR　combination　and　burner　separation　distance　were　varied.　The　results　showed　that　the　asymmetric　flow　characteristic　was　found　in　both　the　flame　and　the　smoke　plume　zone.　In　the　flame　region,　the　flame　morphology　in　terms　of　the　tilt　angle　is　a　good　parameter　indicating　the　asymmetric　flow　characteristic.　In　general,　the　tilt　angle　of　the　small　fire　is　larger　than　that　of　the　big　fire.　The　tilt　angle　of　the　small　fire　decreases　while　that　of　the　big　fire　increases　until　equaling　to　each　other　under　the　HRR　ratio　reaching　unity.　In　the　smoke　plume　region,　the　smoke　plumes　from　the　small　and　the　big　fire　will　converge　at　a　certain　height　with　some　shifting　distance,　which　is　another　parameter　indicating　the　asymmetric　flow　characteristic.　Besides,　the　smoke　plume　merging　process　driven　by　asymmetric　air　entrainment　can　be　divided　into　three　stages,　namely　the　I)　Separate　stage,　II)　Converging　stage　and　III)　Complete　coalescence　stage.　Correlations　of　the　converging　&　coalescence　height　suggesting　the　starting　point　of　the　II　and　III　stages　were　proposed.　©　2021,　The　Author(s),　under　exclusive　licence　to　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature.