This chapter covers the impedance matching and energy conversion (1). Smith chart and matching circuit design method are explained. First, the circuit impedance matching method is summarized. Design of matching circuit using Smith chart and impedance chart and admittance chart are explained. Trajectories on Smith chart are explained for cases of connecting C in series to a load, connecting L in series to a load, connecting R in series to an impedance load, connecting C in parallel to a load, connecting L in parallel to a load, connecting R in parallel to an impedance load, and connecting a transmission line to an impedance load. The chapter is concluded by the conclusions and exercise problems.