＂aged＂　biofilter　media　was　adopted　as　the　inoculum　to　accelerate　the　maturation　of　biofilter　for　iron　and　manganese　removal　in　the　start-up　of　filter　column.　morphology　of　＂aged＂　biofilter　media　and　new　quartz　sand　was　observed　with　SEM.　The　results　indicate　that　the　＂aged＂　biofilter　media　coated　by　a　large　quantity　of　bacteria　which　reduces　the　start-up　time　to　30　daysand　affords　strong　Mn-removal　efficiency　at　the　beginning　of　the　process.　This　method　probably　can　be　used　for　the　start-up　of　new　filters　when　there　are　well-established　biofilters　around.