An automotive head lamp module consists of various components. The components have the structural stiffness for sustaining the module and functional characteristics such as optical characteristics, high heat conductivity and surface glossy etc. Especially, the reflector housing is usually made from aluminum or magnesium for the sake of structural safety of inner lens assembly and fast radiation of heat from the light source. From the industrial stream for a lightweight vehicle, it is tried to substitute the metallic reflector housing to plastic one with high strength and heat-resistivity. This attempt will induce the enhancement of the efficiency of weight and manufacturing cost. In this paper, the numerical analysis is performed to evaluate the adaptability of poly-phenylene sulfide(PPS) as the material of the reflector housing. First, to define the thermal boundary condition of the reflector housing in the working state of the lamp module, temperature distribution of the existing magnesium housing is measured at 12 points of inner and outer part. And heat flux radiated from the bulb is calculated through the heat transfer numerical analysis by comparing the experimental temperature distribution to the simulated one according to the variation of the heat flux of the bulb in the module. The material properties such as stress-strain relation and thermal properties according to temperature range from 25�Ž to 150�Ž, are obtained to apply the temperature dependent material properties to the heat transfer analysis of PPS reflector housing. The analysis result shows that the heat does not effectively radiated to outer surface and localized at inner surface. However, the thermal stress does not exceed the 20% of the ultimate strength of PPS except for some highly heat localized zone. And, for release of the localized heat, the heat radiation pin structures and nano filler PPS compound with higher thermal conductivity are suggested.