Photosystem Ⅱ (PSⅡ) is an important supramolecular complex located in the thylakoid membranes of plants, algae and cyanobacteria. Powered by the energy harvested from light, PSⅡ carries out energy conversion through charge separation in the reaction center, drives the primary electron transport process and splits water molecules into oxygen and protons under ambient temperature and pressure. At the peripheral region of plant PSⅡ, there is a pool of major and minor light harvesting complexes Ⅱ (LHCⅡ) responsible for absorbing light energy and transferring excitation energy to PSⅡ. They are also involved in the regulation of light harvesting through the non-photochemical quenching and state-transition processes. In recent years, tremendous progresses have been made in structural biology studies of plant PSⅡ-LHCⅡ supercomplexes. Here we review the history and latest progresses concerning the structures of PSⅡ, LHCⅡ and the PSⅡ-LHCⅡ supercomplexes, and discuss the perspectives for future research.