The　development　of　direct　conversion　for　selective　functionalization　of　inert　methane　plays　an　important　role　in　the　chemical　sciences.　Here,　we　report　a　photocatalytic　approach　to　successfully　convert　methane　into　methyl　chloride　over　NaTaO3　photocatalyst　using　an　alkali　chloride　solution　as　the　chlorine　source　under　ambient　conditions,　which　can　overcome　disadvantages　of　toxicity　and　corrosiveness　in　the　traditional　chlorination　of　methane.　Various　noble　metals　and　oxide　cocatalysts　(Pt,　Pd,　Au,　Ag,　and　Ag2O)　and　different　chloride　ion　solutions　(NaCl,　KCl,　LiCl,　MgCl2,　BaCl2,　CaCl2,　CuCl2,　FeCl3,　ZnCl2,　etc.)　are　investigated　to　optimize　the　photocatalytic　chlorination　processes.　Ag2O/NaTaO3　is　the　best　photocatalyst,　giving　the　maximum　CH3Cl　yield　of　152　mu　mol　g(-1)　h(-1)　in　aqueous　NaCl　solutions　and　an　apparent　quantum　yield　of　7.2%　under　254　nm　monochromatic　light　irradiation.　The　target　product　CH3Cl　is　verified　to　be　formed　by　a　direct　combination　of　the　photoinduced　species　center　dot　CH3　and　center　dot　Cl　on　the　Ag2O　surface.　This　work　provides　a　meaningful　approach　for　the　conversion　of　methane　into　chloromethane　under　normal　conditions.