Friction exists in all machines having relative motion, and plays an important role in many servo mechanisms and simple pneumatic or hydraulic systems. In order to achieve high precision motion control, accurate friction modeling and effective compensation techniques have to be investigated. In this chapter, we shall present a systematic treatment of adaptive friction compensation techniques from both engineering and theoretical aspects. Firstly, a comprehensive list of the commonly used classical friction models and dynamic friction models is presented for comparison and controller design. Then, by considering the position and velocity tracking control of a servo mechanism with friction, adaptive friction compensation schemes are given based on the LIP static friction model and dynamic LuGre model respectively. Finally, extensive simulation comparison studies are presented to verify the effectiveness of the proposed methods.