Abstract: Nitrogen is one of the most important elements for organisms, which is keep cycling in a special way in nature. Traditional nitrogen cycle was believed to be the one way for nitrogen conversion, however, with the development of biotechnology, new nitrogen conversion pathway was discovered, which becomes hot points for researchers. In the manuscript, we summarized the discovery and research status of anaerobic ammonium oxidation (anammox) and archaeal aerobic ammonia-oxidation processes. Moreover, future investigation and application for anaerobic ammonium oxidation and archaeal aerobic ammonia-oxidation processes were also overviewed.