Biological　manganese　removal　process　has　a　problem　of　long　start-up　period,　when　it　is　adopted　to　purify　groundwater　containing　high　concentration　of　iron,　manganese　and　ammonia　nitrogen.　In　order　to　investigate　the　effect　of　circulation　reflux　on　start-up,　three　starting　modes　with　varying　reflux　ratio,　constant　reflux　ratio　and　no　reflux　were　adopted　in　three　same　filters.　Results　showed　that　the　total　iron,　manganese　and　ammomia　nitrogen　in　effluent　of　the　three　filters　was　below　0.3　mg/L,　0.05　mg/L　and　0.2　mg/L　on　51,　61　and　82　day,　respectively;　Variation　of　iron,　manganese　and　ammonia　nitrogen　removal　along　the　filter　showed　that　the　iron　was　removed　mainly　in　the　depth　of　0-0.4　m,　the　manganese　was　adsorbed　by　manganese　sand　at　the　beginning　and　biological　manganese　removal　was　improved　gradually　after　ammonia　nitrogen　reduced　to　be　low　enough.　The　circulation　reflux　is　an　effective　way　to　shorten　the　start-up　period　of　biological　manganese　removal　process　with　high　concentration　of　iron,　manganese　and　ammonia　nitrogen.