The continuous development of industrial electronics technologies, small-size and high-power density designs became a development trend. Thus, high and very high frequency power supplies received widespread attention. One major advantage of improving the working frequency is to achieve total volume reduction of passive components, and therefore effectively reduce system size and improve power density. Moreover, in some cases, even parasitic parameters of a system working at high and very high frequency can also be used as the passive element. Besides, electrolytic capacitors can be removed thereby greatly extending the system lifetime. The dynamic response can also be accelerated. At the same time, the third generation of wide bandgap semiconductors such as SiC and GaN with material properties superior to their Si counterparts, creates new opportunity and challenges for innovation of power converters such as compact design, thermal management, electromagnetic interference etc. With the maturity of these devices, it provides a broad space for development of high and very high frequency power supplies. Nevertheless, topologies, driving methods, control strategies and many aspects require deep investigation with the increment of switching frequencies. We encourage all researchers working in this area to submit papers to this Special Section.