A new numerical simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings of the Second JSME-KSME Thermal Engineering Conference, pp. 3-345-3-348, 1992]. in this model, the boiling curve is reproduced numerically by determining the macrolayer thickness. It is found that the evaporation due to the growth of vapor stem is the main contribution to the total heat flux. In addition, the formation of nucleation site density is considered and the effect of surface roughness is investigated. Furthermore. the model is applied in the transient boiling process. The transient boiling curves are predicted through increasing power linearly and exponentially. The saturated liquid fluorinert FC-72 and water are used in the numerical calculation. Finally, this: model is combined with three-dimensional transient heat conduction to investigate the spatial variations of wall temperature,