The　slow　initiation　of　anammox　for　treating　typical　domestic　wastewater　and　the　relatively　high　footprint　of　wastewater　treatment　infrastructures　are　major　concerns　for　practical　wastewater　treatment　systems.　Herein,　a　300　m(3)/d　hybrid　biofilm　reactor　(HBR)　process　was　developed　and　operated　with　a　short　hydraulic　retention　time　(HRT)　of　8　h.　The　analysis　of　the　bacterial　community　demonstrated　that　anammox　were　enriched　in　the　anoxic　zone　of　the　HBR　process.　The　percentage　abundance　of　Candidatus　Brocadia　in　the　total　bacterial　community　of　the　anoxic　zone　increased　from　0　at　Day　1　to　0.33%　at　Day　130　and　then　to　2.89%　at　Day　213.　Based　upon　the　activity　of　anammox　bacteria,　the　removal　of　ammonia　nitrogen　(NH4+-N)　in　the　anoxic　zone　was　approximately　15%.　This　showed　that　the　nitrogen　transformation　pathway　was　enhanced　in　the　HBR　system　through　partial　anammox　process　in　the　anoxic　zone.　The　final　effluent　contained　12　mg/L　chemical　oxygen　demand　(COD),　0.662　mg/L　NH4+-N,　7.2　mg/L　total　nitrogen　(TN),　and　6　mg/L　SS,　indicating　the　effectiveness　of　the　HBR　process　for　treating　real　domestic　wastewater.