Resonant power conversion is an effective technology for various applications. This paper presents a resonant magnetizing approach, aimed at improving the low power density and cost issues of traditional capacitor-discharged impulse magnetizer. In the method, a resonant tank is established by a series capacitor and inductor. Then, by periodically switching power transistors inside the circuit, the series resonance is triggered so that the output voltage can oscillate higher than the input, naturally obtaining larger current output for magnetization. Moreover, with the aids of high-frequency circuit design and the natural inductive properties of the load, magnetizing process can repetitively operate several times in a few milliseconds. The magnetizing current is thus further cumulative. To validate the effectiveness of the method, both computer simulations and hardware tests are examined. The testing results confirm that the proposed circuit can output the required magnetizing current, helping consolidate the practicability of the studies for the considered applications.