Abstract: The experimental investigation was conducted for the fuel circumferential staging combustor with two domes to improve the lean blowout fuel air ratio.The effects of inlet temperature and inlet velocity were taken into account.Three pieces of clapboard with different length were placed between two domes to eliminate their mutual effects.Results showed that the combustor with fuel circumferential staging could obviously improve fuel air ratio at lean blowout.When the inlet temperature was lower than 400 K,fuel air ratio at lean blowout would decrease obviously with the rising of inlet velocity.When the inlet temperature was higher than 400 K,it wouldn't be sensitive to the inlet temperature and inlet velocity.However,the method was not so good in respect of reducing fuel air ratio at lean blowout by inserting clapboard into two domes.