In　the　present　paper,　we　address　the　influence　of　surface　tension　on　the　mode-I　crack　tip　field,　which　is　modeled　as　a　curvature　dependent　normal　traction　acting　along　the　crack　surface.　Through　finite　element　simulations,　we　examine　the　stress　field　and　the　J-integral　around　the　crack　tip.　It　is　found　that　when　the　curvature　radius　at　the　crack　root　reduces　to　nanometers,　surface　tension　significantly　alters　the　stress　state　near　the　crack　tip.　Surface　tension　leads　to　compressive　stress　along　the　symmetric　plane　and　prominent　shear　stress　adjacent　to　the　symmetric　plane.　Moreover,　surface　tension　decreases　the　J-integral　and　thus　has　a　tendency　to　enhance　material　toughness.　The　sharper　the　crack　root,　the　more　significant　the　influence　of　surface　tension.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.