The cutting temperature is a key factor which directly affects thermal distortion, the machined part’s dimensional accuracy, as well as the tool wear in machining process. Aiming to effectively remove the cutting heat yields in machining process, the cutting tool with heat pipe cooling has been developed in recent years. This research focuses on developing a clear understanding of the temperature distribution in end mill embedded with heat pipe. Mathematical model is developed based on the heat transfer theory and the metal-cutting theory. 3-D finite element models are set up. The thermal boundary conditions are properly set, and contrasts of the temperature field in end mill with and without embedded heat pipes by numerical simulations are given.