摘要： Microstructured surfaces have been adopted in various and wide applications. Different types of microstructures made of ductile materials can be generated by cutting process, for example, turning and milling with speci?ed diamond cutters. However, these processes generally are not capable to handle with hard and brittle materials which are called dif?cult-to-machine materials. Computer-controlled ultra-precision polishing with bonnet provides an enabling solution to generate microstructures due to its feasible in?uence function. With proper machining parameters, speci?ed shape of the tool in?uence function is hence obtained, and then with aid of tool path planning, microstructured surface topography is generated, especially for those dif?cult-to-machine materials. In this chapter, research work for generating microstructured surface by computer-controlled ultra-precision bonnet polishing is presented. The material removal characteris- tics and tool in?uence function of bonnet polishing are explained, and a multi- scale material removal model and a surface generation model were developed. Surface generation of microstructures by single precess polishing and swing precess polishing is explained in details. A series of simulation and real polishing experimental studies are undertaken based on a seven-axis ultra-precision freeform polishing machine. The generated microstructured surfaces with various patterns have been analyzed. The research results have demonstrated that the proposed bonnet polishing provides an enabling and effective approach for generating microstructured surfaces.