The　circular　mesh　antenna　is　designed　as　a　lightweight　and　flexible　structure　in　the　orbit　and　use　mainly　metal　meshes　as　a　reflecting　surface.　This　paper　analyzes　frequencies　and　modal　shapes　of　the　circular　mesh　antenna　by　using　the　finite　element　method,　and　the　nonlinear　resonant　responses　of　the　circular　mesh　antenna　are　studied　based　on　a　circular　cylindrical　shell　equivalent　model　clamped　along　a　generatrix　and　with　membranes　at　both　ends.　Firstly,　we　establish　the　finite　element　model　of　the　circular　mesh　antenna　considering　the　influences　of　meshes　on　the　vibration　characteristics　of　the　circular　mesh　antenna.　It　is　found　that　there　exist　the　1:3　internal　resonance　under　a　certain　mesh　stiffness　between　the　first-order　and　the　fourth-order　vibrations　of　the　circular　mesh　antenna,　and　we　give　the　comparison　of　the　first　six　orders　vibration　modal　shapes　under　the　different　mesh　stiffness　cases　to　study　the　influences　of　mesh　stiffness　on　the　vibration　modal　shapes　of　the　circular　mesh　antenna.　Then,　we　obtain　the　four-dimensional　nonlinear　averaged　equation　based　on　the　two　degrees　of　freedom　non-autonomous　nonlinear　equations　of　the　circular　mesh　antenna　equivalent　model　considering　this　case　of　1:3　internal　resonance.　At　last,　we　compute　the　curves　of　equilibria　in　order　to　study　the　nonlinear　resonant　responses　of　the　equivalent　circular　mesh　antenna　model.　The　amplitude-frequency　response　curves　and　the　parametric　excitation　amplitude　curves　of　the　system　on　the　state-parameter　space　are　obtained,　meanwhile,　jump　points　and　Antronov-Hopf　points　are　detected　and　located　on　these　resonance　response　curves.　Furthermore,　the　effects　of　temperature　excitation　on　amplitude-frequency　response　curves　of　the　equivalent　circular　mesh　antenna　model　are　investigated　©　Proceedings　of　the　26th　International　Congress　on　Sound　and　Vibration,　ICSV　2019.　All　rights　reserved.