To　improve　the　performance　of　electrostatically　actuated　valveless　micropump,　simulation　of　its　dynimic　characteristics　have　been　conducted　by　full　electrostatic-mechanic-fluidic　coupled　model　(CFM)　and　prescribed　deformations　model　(PDM)　respectively.　By　comparing　the　calculated　results　of　diaphragm　deflections,　transient　variations　of　central　displacements,　chamber　pressures　and　flow　rate　of　inlet/outlet,　it　can　be　concluded　that　the　PDM　has　lower　cost　and　inadequate　precision,　but　some　distorting　dynamic　characteristics　may　be　resulted　from;　The　FCM　can　predict　the　transient　behaviors　of　the　micropump　quite　well　since　the　effects　of　electro-mechanical　coupling　and　fluid-structural　interaction　have　been　considered,　but　the　computation　cost　is　much　more　expensive.