The　mass　transfer　performance　of　packing　is　one　of　the　main　determinants　of　its　treatment　effectiveness.　To　improve　the　diffusion　ability　of　PVA　gel,　its　mass　transfer　performance　was　studied　by　a　single-factor　test　to　determine　the　effect　of　the　activated　carbon　and　CaCO3　contents　on　the　mass　transfer　performance.　The　mass　transfer　performance　was　optimized　using　response　surface　methodology　(RSM).　The　results　show　that　adding　the　appropriate　amount　of　activated　carbon　and　CaCO3　can　effectively　improve　the　mass　transfer　performance　of　PVA　gel.　Under　the　optimized　conditions,　the　effective　diffusion　coefficients　of　NH4+-N,　NO2--N,　and　NO3--N　in　PVA　gel　were　1.363　7×10-9,　1.085　0×10-9,　and　1.019　9×10-9　m2·s-1,　respectively.　©　2017,　Science　Press.　All　right　reserved.