The　effect　of　doping　IB　metals　(Cu,　Ag,　and　Au)　on　the　photocatalytic　activity　of　monoclinic　Bismuth　vanadate　(BiVO4)　was　investigated　by　predicting　their　electronic　and　optical　properties　based　on　the　first-principle　calculation.　For　the　Cu-doped　system,　the　formation　of　shallow　acceptor　level　will　narrow　the　band　gap　and　trap　the　electrons　which　may　enhance　the　separation　of　photoinduced　carriers.　And　the　doping　of　Ag　has　little　effect　on　the　electronic　structure.　However,　the　doping　of　Au　will　introduce　a　deep　localized　impurity　level　which　should　serve　as　both　charge　traps　and　recombination　centers,　and　hinder　the　separation　of　photo-induced　carriers.　With　incorporation　of　Cu,　the　mobility　of　charge　carriers　is　enhanced　due　to　the　smaller　effective　mass,　but　the　Ag　and　Au　doping　would　not　improve　the　transfer　of　charges.　In　summary,　only　the　doping　of　Cu　has　positive　effect　on　improving　the　photocatalytic　activity　of　monoclinic　BiVO4.　(C)　2015　Wiley　Periodicals,　Inc.