In　this　paper,　polyvinylidene　fluoride　(PVDF)/polymethyl　acrilate　(PMMA)/cellulose　acetate　(CA)　blend　UF　membranes　were　prepared　by　chemical　reaction　introduced　phase-inversion　method.　The　results　of　the　experiment　show　that:　(1)　The　membrane　pore　size　distribution　is　more　uniform　due　to　the　presence　of　carbonates　or　bicarbonates　in　the　coagulation　bath;　(2)　No　more　than　the　stoichiometric　ratio　amount　of　carbonates　or　bicarbonates　in　the　coagulation　bath　can　effectively　improve　the　membrane　pore　size　distribution　and　make　the　pore　size　of　membrane　more　uniform;　(3)　The　membrane　prepared　by　carbonates　solution　as　a　working　solution　in　coagulation　bath　possess　superior　performance　than　that　by　bicarbonates.　(C)　2010　Elsevier　B.V.　All　rights　reserved.