This paper proposes a novel soft-switching circuit without using additional active switch for SiC-based DC-DC boost converters. The proposed circuit can reduce the turn-on loss of the SiC switch and the diode reverse recovery loss by adding a small inductor in series with the switch. Since there is no auxiliary switch, the control method of the proposed boost converter is the same as that of the conventional one. A 2-kW SiC-based boost converter that can step up 300 V to 600 V at 90 kHz switching frequency has been designed. Experimental results have shown that the turn-on loss of the SiC switch is reduced by 66% under the rated condition compared with that of the hard-switching boost converter.