High efficiency milling experiment of natural marble using CVD diamond coated tool were carried out to study the characteristics of cutting force and quality during the cutting of natural marble.The mathematic model of principal cutting force was built based on the toolworkpiece contact geometry.The changing features of cutting force of different types of cutting tools and the surface roughness of natural marble with cutting parameters and time were analyzed.The results show that the cutting force of three directions of CVD diamond coated tools is much smaller than that of uncoated tools.The variation trend of cutting force with cutting parameters is basically identical for the two types of tools.The changing process of cutting force can be divided into four stages:initial grindingin stage,stabilization stage,transitory stage and intensification of tool wear stage.The runingin period and stable period of CVD diamond tool is 35 times that of uncoated tools,and the cutting force and the surface roughness of workpiece changed smoothly.However,there is a very short cutting stable period and a significant increasing trend on the cutting force of uncoated tool,during the last growth period of cutting force,the surface roughness is increased to 2.5 μm.