Abstract: Principle of magnetic resonance coupling wireless power transmission system was analyzed by use of mutual inductance theory. Impedance matching theory and corresponding parameter calculation methods were introduced. A model of magnetic resonance coupling wireless power transmission system containing an impedance matcher was built by equaling variation of mutual inductance between sending coil and receiving coil to variation of the system impedance parameters. The simulation result proves that magnetic resonance coupling wireless power transmission system containing an impedance matcher can improve load power effectively under the same condition.