In　recent　years,　membrane　ultrafiltration　(UF)　of　surface　water　for　drinking　water　treatment　has　become　a　more　attractive　technology　worldwide　as　a　possible　alternative　treatment　to　conventional　clarification.　To　evaluate　the　performance　of　ultrafiltration　membranes　for　treatment　of　surface　water　in　North　China,　a　48-m(2)　low　pressure　hollow　fiber　membrane　ultrafiltration　pilot　plant　was　constructed.　Ultrafiltration　was　operated　in　cross-flow　and　with　powdered　activated　carbon　(PAC)　adsorption.　Turbidity　was　almost　completely　removed　to　less　than　0.2　NTU　(below　Chinese　standard　1　NTU).　It　was　found　that　PAC　addition　enhanced　organic　matter　removal.　The　combined　process　of　PAC/UF　allowed　to　41%　removal　of　CODMn,　46%　removal　of　DOC　and　57%　decrease　in　UV254　absorbance.　The　elimination　of　particles,　from　average　12000/ml　in　the　raw　water　to　approximately　15/ml　in　the　permeated,　was　observed.　When　PAC　concentration　was　below　30　mg/L,　backwashing　could　recovery　the　membrane　flux　with　backwash　interval/backwashing　duration　of　1/30.