Abstract: The calculation of the radiation heat-flux on combustor wall and in outlet by Monte-Carlo method takes into account the effects of radiation energy emitted from any single element on all other elements.The calculation gives better prediction of the radiation process in a gas turbine combustor.The radiation heat-flux densities of combustor wall and outlet can be calculated by Monte-Carlo method,provided the temperature,dioxide-carbon partial pressure and water vapor partial pressure distribution in a combustor are known.The changes of gas absorptivity and emissivity in the combustor have been taken into account.A complete computation procedure and related error analysis have been described in detail.A numerical example is given and the calculated results are reasonable.