To　investigate　the　maximum　concentration　of　manganese　of　groundwater　containing　high　concentration　of　iron,　manganese　and　ammonia　nitrogen　groundwater　in　a　biological　iron　and　manganese　removal　filter,　a　mature　and　steady　operated　biological　filter　was　used,　and　the　concentration　of　manganese　in　influent　was　increased　gradually.　Results　showed　that　in　the　experimental　conditions　of　the　concentration　of　total　iron　and　ammonia　nitrogen　was　5-10,　0.9-1.3　mg/L,　respectively,　the　temperature　of　raw　water　was　8°C,　and　the　flow　rate　was　6　m/h,　when　the　dissolved　oxygen　(DO)　in　influent　was　about　8.5　mg/L,　the　maximum　concentration　of　manganese　was　7.5　mg/L;　when　the　DO　was　above　10　mg/L,　the　maximum　concentration　of　manganese　was　10.5　mg/L.　There　was　no　influence　of　manganese　concentration　increased　in　influent　on　iron　and　ammonia　removal.　Variation　of　iron,　manganese　and　ammonia　nitrogen　removal　along　the　filter　showed　that　along　the　filter　depth,　manganese　removal　quantity　reduced　in　the　same　depth　of　the　filter,　the　efficiency　of　ammonia　removal　did　not　change　along　the　filter　depth　in　manganese　concentration　increased　process.　The　maximum　concentration　of　manganese　was　limited　by　DO,　the　DO　in　influent　was　higher,　the　concentration　of　manganese　was　higher.