The　panel　flutter　of　composite　plate　with　viscoelastic　mid-layer　in　supersonic　airflow　is　investigated　in　this　study.　The　hysteric　damping　model　is　used　to　describe　the　viscoelastic　property　of　the　mid-layer　material　and　the　first　piston　theory　to　model　the　aerodynamic　forces.　Hamilton＇s　principle　is　employed　to　derive　the　partial　differential　equations　governing　the　vibrations　of　the　laminated　composite　plate.　By　Galerkin　method　the　governing　partial　differential　equations　are　truncated　into　a　set　of　ordinary　differential　equations.　The　critical　dynamic　pressure　for　panel　flutter　has　been　studied　by　considering　the　eigenvalue　problem　of　the　set　of　ODEs.　It　was　concluded　that　the　introduction　of　aerodynamic　damping　postpones　the　threshold　of　flutter,　while　the　viscoelastic　damping　of　the　soft　mid-layer　presents　a　phenomenon　of　dual　effect.　When　the　viscoelastic　damping　value　is　low,　the　internal　material　damping　shows　detrimental　effect　to　the　flutter　depression.　If　the　viscoelastic　damping　is　increased　further,　the　flutter　resistance　of　the　composite　plate　will　be　enhanced.　The　convergence　of　the　Galerkin　method　is　also　discussed　in　this　study.　The　influences　of　some　parameters　to　the　convergence　have　been　investigated　in　details.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.