Based　on　mechanics　of　anisotropic　material,　the　dynamic　crack　propagation　problem　of　I/II　mixed　mode　crack　in　an　infinite　anisotropic　body　is　investigated.　Expressions　of　dynamic　stress　intensity　factors　for　modes　I　and　II　crack　are　obtained.　Components　of　dynamic　stress　and　dynamic　displacements　around　the　crack　tip　are　derived.　The　strain　energy　density　theory　is　used　to　predict　the　dynamic　crack　extension　angle.　The　critical　strain　energy　density　is　determined　by　the　strength　parameters　of　anisotropic　materials.　The　obtained　dynamic　crack　tip　fields　are　unified　and　applicable　to　the　analysis　of　the　crack　tip　fields　of　anisotropic　material,　orthotropic　material　and　isotropic　material　under　dynamic　or　static　load.　The　obtained　results　show　Crack　propagation　characteristics　are　represented　by　the　mechanical　properties　of　anisotropic　material,　i.e.,　crack　propagation　velocity　M　and　fiber　direction　a.　In　particular,　the　fiber　direction　a　and　the　crack　propagation　velocity　M　give　greater　influence　on　the　variations　of　the　stress　fields　and　displacement　fields.　Fracture　angle　is　found　to　depend　not　only　on　the　crack　propagation　but　also　on　the　anisotropic　character　of　the　material.　(C)　2009　Elsevier　Ltd.　All　rights　reserved.