This work is connected to the modelling of the fire growth in a room, for which the knowledge of the radiation emitted by the flames to surrounding combustible elements is significant.Working on propane diffusion flames rising above the surface of a 0.3 m diameter circular burner, we have established the radiative flux distributions in vertical planes facing the fire.The radiative fraction χ has been measured; χ increases first with fuel flow rate and then reaches anasymptolic value. Starting from measured temperature distributions, the radiation fluxes emitted by the nonisothermal flames have been computed and compared with values obtained making constant flame properties assumption, and with experimental values.