The　chaotic　motion　and　its　control　of　a　two-dimensional　simply　supported　thin　plate　with　geometric　nonlinearity　subjected　to　subsonic　air　flow　and　transverse　periodical　load　are　studied.　Based　on　von　Karman＇s　plate　theory　and　the　variable　separation　method,　the　equation　of　motion　of　the　thin　plate　under　subsonic　air　flow　is　established.　For　the　uncontrolled　system,　the　Melnikov＇s　method　is　used　to　predict　the　threshold　values　for　the　chaotic　motion,　and　the　results　are　verified　numerically　through　the　Runge-Kutta　method.　For　the　system　under　chaotic　motion,　the　time-delayed　feedback　control　is　used　to　control　the　chaotic　motion　of　the　plate.　From　the　analytical　and　numerical　results,　it　is　shown　that　the　Melnikov＇s　method　is　effective　in　estimating　the　threshold　values　for　the　chaotic　motion,　and　the　time-delayed　feedback　control　method　can　effectively　transform　the　chaotic　motion　of　the　plate　into　periodical　one.