Nickel-based super alloy GH4169 has been widely used in aerospace industry because of its good mechanical properties under high temperature. However, it is difficult to machine for its high strength, poor thermal conductivity and serious work-hardening. The effects of tool geometric parameters on tool life are studied by machining experiments using YG8 tools with different cutting edge angle in this paper. The tool with cutting edge angle 45°has longer tool life than 75°. The cutting experiments have been carried out using TiAlN (PVD) coated tools (AC520U) with different rake angle. It shows that the tool life with rake angle 9° were increased by 50% and 25% compared to tool with rake angle 3°and 6° when cutting speed is 30m/min. The tool with rake angle 9° is not suitable for cutting GH4169 when cutting speed is more than 35m/min. The results show that geometric parameter of cutting tool is one of the important factors affecting tool life.