Abstract: A numerical method for an ionized hypersonic air flowwith radiation under thermo-chemical nonequilibrium condition has beendeveloped with multi-species N-S equations based on unstructured mesh. Inthe algorithm, there are 11 chemical species (O_2, N_2, O, N,NO, NO^+, N^+, O^+, N_2^+, O_2^+, e^ - ), 20 chemicalreactions, and two temperature models subjectedto thermal nonequilibrium effect. Radiation transfer equation (RTE) wassolved by finite volume method. In particular, the Delta, Epsilon, Beta primeand Gamma prime bands of NO were introduced in this paper. The numericalresults of MUSES-C were shown and compared well with the reference data. Theinfluence of radiation was also discussed.