In　a　laboratory-scale　experimental　setup,　slow　biological　activated　carbon　(SBAC)　filtration　was　conducted　to　control　membrane　fouling　during　ultra　filtration　(UF)　of　artificial　raw　water,　and　the　underlying　mechanism　of　fouling　control　was　analysed　by　various　means.　The　trans-membrane　pressure　(TMP)　during　the　experimental　SBAC-UF　was　60.2%　lower　than　that　of　UF　performed　without　SBAC.　The　best　fit　of　classic　filtration　models　indicated　that　SBAC　did　not　change　the　fouling　model,　with　standard　blocking　and　cake　formation　as　the　main　fouling　mechanisms,　but　it　reduced　the　extent　of　the　fouling.　Organic　material　was　investigated　and　particle　characteristics　were　determined　to　analyse　their　role　in　fouling　control.　Protein-like　substances　were　demonstrated　to　be　major　components　of　deposited　foulants,　and　these　could　be　effectively　removed　by　SBAC.　Fewer　particles　were　present　in　SBAC　effluent,　while　their　size　distribution　was　narrower.　This　led　to　formation　of　a　thinner　cake　layer　on　fouled　membranes　compared　to　membranes　fouled　with　untreated　raw　water.　In　summary,　SBAC　filtration　can　control　membrane　fouling　by　specific　removal　of　protein-like　substances　and　favourably　affect　the　quantity　and　size　distribution　of　remaining　particles.