In this study, a three-dimension ray tracing and transient thermal simulation is developed to evaluate the thermal condition of injection mold surface with infrared surface rapid heating system. Several types of reflectors were applied to study the heating ability of the rapid surface heating system. A commercial available optical analysis program, TracePro, was used to simulate the infrared absorption of the mold surface. The surface temperature of the mold insert was evaluated by 2D and 3D transient thermal analysis with a commercial software, ANSYS. The results from simulation and thermal video measurement system agree well. Besides, the temperature distribution of the mold surface can be better observed via the 3D thermal analysis developed in this article. (c) 2006 Elsevier Ltd. All rights reserved.