Taguchi method was applied to optimize the performances of TiAlN coatings deposited by hollow cathode discharge ion plating (HCDIP) and medium frequency magnetron sputtering ion plating (MFMSIP) hybrid physical vapor deposition (PVD) coating system. TiAlN coatings prepared by this coating system showed columnar microstructure with the preferred orientation of (1 1 1). The sensitive parameters on microhardness were total deposition pressure and substrate bias voltage, and the sensitive parameter on milling performance was substrate bias voltage. The optimum conditions were total deposition pressure: 0.9 Pa,. flow rate of N-2: 250 sccm, substrate bias voltage: -120 V. And the confirming experiment obtained the optimum TiAlN coating with microhardness of 25.8 GPa, and the best TiAlN-coated end mill performed the milling length of 50.8 m. (C) 2008 Elsevier B. V. All rights reserved.