Oxidative phosphorylation is a biochemical pathway responsible for generation of most of the eukaryotic cell’s energy and is strictly dependent of oxygen. It originated in Bacteria and was introduced into the Eukaryotic cell through an endosymbiotic event, where it has been expanded and modified. However, the exact time of the origin and expansions is still not clear. There have been attempts to time these events, but their resolution was mostly poor due to use of few sequenced genomes. In this study I used the genomic phylostratigraphy approach to study macroevolutionary transitions in the evolution of the oxidative phosphorylation pathway. The results show three periods of major adaptations during the evolution of OXPHOS pathway: (1) the origin of cellular organisms, (2) the origin of Opisthokonta, and (3) the origin of Bilateria. It is interesting to note that the origin of Bilateria correlates with a large increase in oxygen concentrations in the Earth’s atmosphere and oceans, as well as the appearance of the first large multicellular organisms.