Abstract: In order to evaluate the accuracy and applicability of a two-step chemical scheme for kerosene in supersonic combustion under low total temperature, computations of the three-dimensional combustion flow field of scramjet have been performed with this model. The results were obtained with the combustor configurations including a rectangular combustor with single-cavity and a circular combustor with dual-cavity, and with the total temperature including 950 K and 600 K. Results show that the simulated wall pressure and combustion flow field are in agreement with the experiments, and the simulated flow field can accurately reflect the chemical energy release during the combustion process. As expected, more overall information of combustion flow field including the flow structure, the physical variable distribution and the combustion mode can be obtained by analyzing the numerical results.