The combustion characteristics at atmospheric pressure for a co-axial double swirler combustor have been investigated.The results show that its combustion performances can be significantly improved by increasing properly swirl number for inner swirler

as outer and inner flows are counter-rotating;the annular recirculation zone is a good source for flame stabilization

which is a important factor for extenting the weak extinction limit;The temperature distribution at the exit section of the combustor can be controlled by varying fuel-air ratio of outer and inner swirling flows.