To　gain　the　run　parameters　of　the　combined　process　of　coagulation/in　situ　chlorination/ultrafiltration　(UF)　so　that　the　system　can　remove　as　much　organic　contaminants　as　possible　without　serious　membrane　fouling,　the　impacts　of　operation　conditions　in　coagulation　and　pre-chlorination　unit　were　investigated　in　a　pilot-scale　test.　The　characteristics　of　organics　in　UF　influent　were　examined　by　excitation　emission　matrix　spectroscopy　to　find　out　fouling　behavior　of　different　natural　organic　matter　compositions　to　UF　membrane.　Thereafter,　the　operation　parameters　of　different　processing　units　of　the　hybrid　device　were　optimized　by　response　surface　methodology　(RSM).　The　results　showed　that　the　tests　with　the　agitation　speed　of　40　r　min−1　had　the　lowest　membrane　fouling　rate　and　the　highest　CODMn　removal,　in　addition,　inappropriate　dosage　of　sodium　hypochlorite　in　membrane　influent　might　exert　negative　impacts　on　membrane　by　lowering　UV254　rejection,　especially　during　the　high　algae　laden　period.　The　predominant　factors　of　membrane　fouling　were　the　existence　of　tryptophan　protein-like　substances　and　the　soluble　microbial　products.　Optimum　values　of　the　mechanical　rotation　speed　in　coagulation　unit,　chemical　dosage　in　pre-chlorination　unit,　and　membrane　flux　in　UF　unit　of　the　integrative　process　were　41.79　r　min−1,　1.40　mg　L−1,　and　82.26　LMH,　respectively.　©　2017,　©　2017　Informa　UK　Limited,　trading　as　Taylor　&　Francis　Group.