Despite　the　rapid　increase　of　ultrafiltration　(UF)　membranes　in　water　treatment,　the　UF　performance　in　largescale　drinking　water　treatment　plants　(DWTPs)　in　long-term　operation　has　not　been　well　understood.　This　study　was　carried　out　to　investigate　the　fouling　evolution　of　two　types　of　polyvinyl　chloride　(PVC)　hollow　fiber　UF　membranes　in　a　hybrid　coagulation/short-length　sedimentation/UF　process.　Water　quality　analysis　showed　that　safe　drinking　water　could　be　produced　in　the　life　time　(i.e.,　5　years)　of　the　UF　membranes.　The　fractions　with　large　molecular　weight　(e.g.,　biopolymers),　microbial　by-product　and　aromatic　protein　II　in　raw　water　were　easily　removed,　and　the　formation　potentials　of　most　disinfection　by-products　except　trihalomethanes　were　found　to　decrease　in　the　DWTP.　Constant　filtration　fluxes　were　maintained　for　both　types　of　UF　membranes,　while　PVC　composite　membranes　exhibited　higher　anti-fouling　properties　than　PVC　alloy　membranes.　The　key　fouling　factors　varied　with　operation　time,　and　the　top　three　factors　were　hydraulically　cleaning　efficiency,　temperature　and　chemical　oxygen　demand　using　statistical　analyses.　Finally,　the　evolution　model　of　membrane　fouling　in　the　first　5-year　with　potential　fouling　factors　was　established　using　artificial　neural　network,　and　membrane　fouling　of　another　year　was　predicted　after　UF　membranes　were　replaced　with　new　ones.