Abstract: A 5.8 GHz microwave power transmission system for micro robots is presented.The rectifying circuit model for the microwave power transmission system is established by Ritz-Galerkin(RG) method,and the features of rectifying diode are analyzed.The relations between input power and output voltage as well as the relations between rectifier efficiency and load ratio are derived.The Yagi-Uda antenna is designed to increase directional performance of power receiving.At last,the microwave power transmission experiment system for micro-robots is set up,and the experiment of driving micro-robot using power transmitted by microwave is carried out.Experiment results show that it is feasible to supply power for micro robots by the proposed microwave power transmission system.