A non-isolated high-step-up resonant DC/DC converter made up of a resonant inverter and a passive switched-capacitor (SC) rectifier, is proposed in this paper. The proposed converter is free of transformer and coupled-inductor. Thus, issues related to the leakage inductance and the large volume magnetic component caused by large turn's ratio of high-voltage-gain applications, are avoided. Besides, as the converter contains only one active switch, its control is simple. Second harmonic voltage across the switch is attenuated to provide low voltage stress for the active switch and a higher voltage gain of the converter. The voltage gain of the converter is not achieved by a single stage, but by the gain product of the resonant inverter and SC rectifier. A prototype with input voltage 6 V, 500 kHz switching frequency, 50% duty cycle, is constructed to validate the performance of the proposed converter. The voltage gain of the prototype is over 33 times and the achievable efficiency is close to 90% under a wide load resistance range.