A power factor correct current resonance converter is disclosed which eliminates interference of switching operations between two cascade-connected converter circuits. The power factor correct current resonance converter includes a current resonance converter circuit having switches, a resonance capacitor, a resonance inductor, a transformer, diodes, a smoothing capacitor, and a control circuit. The power factor correct current resonance converter also includes a power factor correct converter circuit having a choke coil, a diode, a smoothing capacitor, and a switch. The switch is turned on or off in response to a voltage produced in a winding of the transformer. Thus, the switching operation of the power factor correct converter circuit is performed in synchronization with the switching operation of the current resonance converter circuit, so that interference of the switching operations is eliminated. In addition, since a dedicated control circuit is not required, the cost can be reduced.