Resonance is a method used to compensate the switching losses. It can be obtained the switching process takes place in the conditions of zero current or zero voltage. With this method, the switching losses can be reduced while the efficiency of the converter will be better, switching devices may be more durable, and can increase the maximum switching frequency. A thorough understanding is necessary in analyzing the operating principle of the equipment of resonant power converter, the characteristic of semoconductor devices used, the switching process, where the current flow, and the wave form of the curve of result. The combination of the method in terms of phase and PSIM are used in this study.