A turbulent combustion simulation to predict the fluid flow, temperature and chemical species concentrations in a jet burner that generates a jet of high temperature and high speed is carried out. Conservative equations of mass, momentum and energy in the turbulent flow field are solved in conjunction with a k-ε turbulence model. A radiative heat transfer model that considers the radiative properties of soot, water and CO2 are included in the simulation. The validity of the numerical model is presented by comparing with the experimental data. The effect of soot on the combustion is also examined. The calculated temperature without considering the soot is higher than the experimental data. However, with considering the soot, the differences between calculated and experimental results become small. The peak temperature is in good agreement with the experimental data. This is because that the soot greatly affects the radiative heat transfer in the burner. Moreover, to improve combustion behavior in the jet burner, a numerical simulation considering a baffle plate that causes recirculation flows is also carried out. As a result, a suitable baffle plate shifts the high temperature region to upstream.