Abstract: One dimension multigroup radiation transfer code (RDMG) was used to simulate the process of radiation transfer in CH foam. The results show that in the same condition of incident flux, the CH density has an remarkable effect on the character of radiation transfer, the processes of thermodynamic equilibrium relaxation of radiation heating matter. When the density is going down, the supersonic heating wave will be substituted for the ablative heating wave in the matter. The character of radiation spectrum also varies with the density in the process of the transfer. In this paper, some detail physical pictures and quantitative results are given.