Abstract: Cotton fiber was treated with an effective flame retardant DFP,which was then incorporated with Cu^{2+ to get flame retardant cotton fiber.Then the flame retarding and smoke suppression of the flame retardant cotton fiber were determined by cone calorimetry.The data show that for the flame retardant cotton fiber,as compared with untreated cotton fiber,the rate of heat release,total heat release and effective heat of combustion are much decreased,which shows that the flame retardant cotton fiber has good flame retarding and smoke suppression effects with much less release of smoke,fume,CO and CO₂ and toxic gas.}