Alternative energy sources to the systems using hydrocarbon fuels have been actively developed due to exhaustion of fossil fuels and issue of global warming by CO 2 . Fuel cells have attracted great attentions to solve these issues as electricity can be produced with product of clean H 2 O by using H 2 -O 2 as a fuel. Besides, using reverse reactions make it possible to produce H 2 and O 2 gas from electrolysis of water. There are various fuel cells systems depending on the types of electrolyte, and in this mini-reviews, the main aim is to focus on perovskite oxides as a catalyst for oxygen-evolution reactions in alkaline electrolysis and its potential to application of alkaline electrolysis systems.