Driven by the increasing global energy demand and environmental requirements, the share of renewable energies in modern power systems is steadily increasing. Among various types of renewable energy generation, photovoltaic (PV) power generation possesses the advantages of high flexibility and broad applicability, making it widely adopted worldwide. It is one of the fastest-growing and most promising forms of renewable energy generation. In this chapter, the development of the PV power generation industry is first introduced. Then, the composition of PV systems and typical classifications of PV inverters are elaborated. The requirements of functions and performances for PV inverters are also discussed from the perspective of users’ demands and grid standard requests. Thereafter, key factors that influence the performances and functions of PV inverter are systematically summarized. At the end of this chapter, the research contents of this book are given according to the above analyses.