Boost converters are popularly employed in equipments for different application. Most renewable power sources, such as photovoltaic power systems and fuel cells, have quite low-voltage output and require series connection or a voltage booster to provide enough voltage output. Several soft-switching techniques, gaining the features of zero-voltage switching (ZVS) or zero-current switching (ZCS) for DC/DC converters, have been proposed to substantially reduce switching losses, and hance, attain high efficiency at increased frequencies. The interleaved boost converter with small input and output current ripples is widely used in recent years. Because of small input and output current ripples, the circuit can reduce the size of the input and output capacitors. Thus, instead of entire system can be improved. From those reasons, ZVT interleaved boost converter can be the most popular candidate. ZVT interleaved boost converter composed of two shunted elementary boost conversion units and an auxiliary inductor. This converter is able to turn on both the active power switches at zero voltage to raise the conversion efficiency. Since the two parallel-operated boost units and identical, operation analysis and design for the converter module becomes quite simple. But the problem is when we design this converter, we cannot easily define the switch capacitances, and also we cannot anticipate this converter’s characteristics. When this converter varies with switch capacitances, the converter’s clamp time and leakage current are changed under each situation. The efficiency and the input current ripple of the converter have some differences in particular. The simulation and experimental results regarding the ZVT interleaved boost converter operation by changing switch capacitance are shown in this thesis.