Heterotrophic　nitrification-aerobic　denitrification　(HN-AD)　shows　innovation　potential　of　wastewater　treatment　process　in　a　single　tank.　However,　how　to　enrich　HN-AD　bacteria　in　activated　sludge　to　enhance　their　contribution　remained　unknown.　This　study　explored　the　impact　of　the　feast/famine　(F/F)　ratio　on　the　succession　of　autotrophic　ammonia　oxidizing　bacteria　(AOB)　and　HN-AD　bacteria　in　a　halophilic　aerobic　granular　sludge　(HAGS)　system.　As　the　F/F　ratio　decreased　from　1/9　to　1/15,　the　total　inorganic　nitrogen　(TIN)　removal　performance　significantly　decreased.　The　proportion　of　heterotrophic　bacteria　was　dropped　from　79.0　%　to　33　%.　Accordingly,　the　relative　abundance　of　Paracoccus　decreased　from　70.8　%　to　25.4　%,　and　the　copy　number　of　the　napA　gene　was　reduced　from　2.2　×　1010　copies/g　HAGS　to　8.1　×　109　copies/g　HAGS.　It　found　the　F/F　ratio　regulated　the　population　succession　of　autotrophic　AOB　and　HN-AD　bacteria,　thereby　providing　a　solution　to　achieve　the　enrichment　of　HN-AD　bacteria　in　HAGS.　©　2023　Elsevier　Ltd