This paper presents a study of the inverse heat conduction problem for high speed machining. A finite element method with an inverse scheme and an experimental measurement using infrared (IR) pyrometer with fiber optic are applied to predict the tool-chip interface temperature and the total heat dissipating to both tungsten carbide and ceramic inserts. A one-dimensional ellipsoidal mapping model of the cutting temperature distribution is adopted here and the average transient cutting temperature is calculated by the inverse finite element method with measured surface temperatures adjacent to the tool edge. Also the analysis of the errors coming from the sensor location and mapping model is studied. The results show the estimated cutting temperature is well convergent and agrees to other previous investigations. It is found that the thermal conductivity of the tool material has significant effect on the heat dissipation but little effect on the tool-chip interface temperature in high speed machining.