Can　an　enterprise＇s　green　technological　innovation　ability　enhance　its　competitiveness?　This　topic　has　not　been　studied　extensively,　there　is　no　consensus　in　the　existing　literature,　and　there　is　no　clear　indication　of　the　underlying　mechanism　and　processes.　In　this　research,　we　establish　a　conceptual　framework　to　describe　the　effect　of　an　enterprise＇s　green　technological　innovation　ability　on　enterprise　competitiveness.　This　model　uses　product　differentiation　as　the　mediating　variable　and　the　enterprise　scale　as　the　moderating　variable.　This　study　is　based　on　a　hierarchical　regression　analysis　of　the　energy　conservation　and　environmental　protection　data　from　enterprises　listed　in　China　from　2011　to　2016.　Our　findings　show　that,　in　general,　the　green　technological　innovation　ability　of　an　enterprise　has　a　significant　positive　effect　on　the　enterprise＇s　competitiveness,　but　different　components　have　different　effects　on　enterprise　competitiveness.　Product　differentiation　has　a　mediating　effect　on　the　relationship　between　an　enterprise＇s　green　technological　innovation　ability　and　competitiveness,　and　its　mediating　effect　differs　depending　on　the　components　of　the　green　technological　innovation　ability.　The　enterprise　scale　positively　moderates　the　relationship　between　the　enterprise＇s　green　technological　innovation　ability　and　enterprise　competitiveness　through　product　differentiation.　This　research　provides　a　new　analytical　framework　to　understand　the　mechanism　underlying　the　effect　of　an　enterprise＇s　green　technological　innovation　ability　on　enterprise　competitiveness,　and　it　also　provides　useful　insights　into　the　development　of　green　technological　innovation　competitiveness　and　the　establishment　of　new　policies　by　the　government　to　improve　the　regulatory　framework　for　green　development.　©　2019　Elsevier　Ltd