A high efficiency current resonance inverter circuit for a discharge lamp includes: a step-up transformer, a primary winding of the step-up transformer having a center tap being connected to a power source side, two other terminals of the primary winding being connected to collectors of two transistors, respectively, emitters of the two transistors being connected to respective terminals of a primary winding of a current transformer having a center tap, the center tap of the current transformer being connected to a ground side. A secondary winding of the current transformer is connected to bases of the two transistors to detect emitter currents of the two transistors in order to detect a resonance current, thereby performing oscillation. When the current resonance inverter circuit is used for a discharge lamp, the need for a conventional collector resonance inverter circuit is eliminated.