The　effect　of　carbon　sources　and　chemical　oxygen　demand　(COD)/NO2--N　ratios　on　the　anammoxdenitrification　coupling　process　of　the　simultaneous　partial　nitrification,　anammox　and　denitrification　(SNAD)　biofilm　was　studied　in　batch　tests.　The　SNAD　biofilm　reactor　was　fed　with　domestic　wastewater　and　filled　with　Kaldnes　rings.　During　the　stable　running　period,　good　SNAD　performance　was　achieved.　The　effect　of　COD/NO2--N　ratios　on　the　anammox-denitrification　coupling　process　was　studied　with　the　carbon　source　of　sodium　acetate.　Consequently,　the　NO2--N　consumption　via　anammox　was　found　to　be　reduced　with　the　increase　of　COD/NO2--N　ratio.　With　the　COD/NO2--N　ratios　of　1,　2,　3,　4　and　5,　the　corresponding　NO2--N　consumption　via　anammox　were　87.1%,　52.2%,　29.3%,　23.7%　and　16.3%,　respectively.　With　the　COD/NO2--N　ranges　of　0　to　2,　the　NO2--N　consumption　via　anammox　was　above　50%,　which　indicated　that　good　nitrogen　removal　performance　was　obtained.　Besides,　the　effect　of　carbon　sources　on　the　anammox-denitrification　coupling　process　was　studied　with　the　COD/NO2--N　ratio　of　5.　With　the　carbon　sources　of　sodium　formate,　sodium　acetate,　sodium　propionate　and　glucose,　the　corresponding　NO2--N　consumption　via　anammox　were　16.3%,　37.1%,　74.1%　and　76.8%,　respectively.　The　SNAD　biofilm　could　operate　good　nitrogen　removal　performance　with　the　carbon　sources　of　sodium　propionate　or　glucose　at　the　COD/NO2--N　ratio　of　5.　©　2017,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.