With　the　development　of　the　wastewater　nitrogen　removal,　new　techniques　and　theories　emerge　continuously.　With　its　unique　advantages,　anaerobic　ammonia　oxidation　(Anammox)　process　becomes　the　most　promising　technology.　As　the　performer　of　anammox　process,　the　known　anammox　bacteria　are　classified　into　five　genera　and　seventeen　species.　They　were　summarized　and　the　quorum　sensing　system　in　intraspecific　relationship　of　anammox　bacteria　was　introduced.　Moreover,　the　competitive　and　synergistic　relationship　between　anammox　bacteria　and　other　bacteria,　including　nitrifying　bacteria,　denitrifying　bacteria　and　anaerobic　methane　oxidizing　bacteria,　was　also　introduced.　Finally,　the　effect　of　common　competitive　factors　on　the　structure　of　anammox　bacteria　population　was　summarized　in　order　to　adjust　the　population　structure　of　anammox　bacteria　by　controlling　these　factors.　In　this　study,　the　microbial　ecology　of　anammox　bacteria　and　wastewater　treatment　process　were　coupled.　Consequently,　a　theoretical　basis　for　the　application　of　anammox　process　in　biological　wastewater　treatment　was　provided.