To study microstructure and mechanical property of TiAlN and TiAlSiN coatings as well as cutting performance and wear behavior of cemented carbide coated cutting tools in cutting SUS304 stainless steel. Nano-micron TiAlN and TiAlSiN coatings were prepared by cathodic arc ion plating on the surface of cemented carbide sample and milling cutter. The thickness of the coating was measured by X-ray fluorescence measurement system. Scanning electron microscopy (SEM) was used to observe coating surface morphology. Energy dispersive spectroscopy (EDAX) was used to analyze coating elements; nano indenter was applied to measure the coating hardness. Rockwell Hardness Tester was implemented to investigate the adhesion strength qualitatively. High speed milling experiment was used to study the cutting performance and wear behavior of coated cutting tools. The thickness of TiAlN and TiAlSiN coatings were 3.32 μm and 3.35 μm respectively. The coating surface is dense and smooth. Droplets, pinholes and shallow craters existed on coating surface when observed under high resolution (20000×). The Si element promoted the growth of TiN (200) crystal phase. The grain size decreased when the hardness increased. The micro-hardness of TiAlN and TiAlSiN coatings were 29.6 GPa and 37.7 GPa respectively. The adhesion strength met the VDI-3198 industrial standard of HF3 and HF1 levels. At high cutting speed of 130 m/min, the life of TiAlSiN coated tool was about 5 times than that of uncoated tool, and 1.5 times than that of TiAlN coated tool. TiAlSiN coating prepared by Si doping has higher hardness and better resistance to adhesion, which is more suitable for high speed machining of stainless steel.