A　method　for　constructing　reduced-order　models　(ROM)　of　an　electrostatically　actuated　clamped　silicon　diaphragm　is　presented.　This　reduced-order　model　is　constructed　by　using　basis　the　spatially　dependent　eigen-functions.　A　commercial　finite　element　package　is　firstly　used　to　form　the　system　mass　and　stiffness　matrices　representing　the　model.　These　matrices　are　then　manipulated　in　MATLAB　(TM)　and　reduced　using　modal　type　dynamic　condensation.　The　eigen-value　problem　is　then　solved　for　the　reduced　mass　and　stiffness　matrices　and　subset　of　the　modes　are　used　to　producing　low-order　but　highly　accurate　models　of　electrostatically　actuated　diaphragm.　The　reduced　order　model　can　accounts　for　general　residual　stress　and　strain　hardening　and　allows　for　any　other　electric　driving　signal　simulations.　Once　the　ROM　has　been　generated,　it　can　be　reused　to　simulate　the　quasi-state　and　dynamics　behaviors　of　the　device　over　a　range　of　different　electric　driving　waveforms.　The　calculated　results　show　that　the　resulting　ROM　can　capture　the　static/dynamic　behaviors　of　the　device　very　well.　The　simulation　results　also　show　good　agreement　with　the　fully　meshed　dynamic　models　simulation　results,　thus　the　efficiency　and　accuracy　of　the　modeling　technology　are　valid.