By　virtue　of　state　space　method,　partial　general　displacements　and　stresses　were　taken　as　state　variables　to　describe　the　movement　of　MEE.　Considering　constitution　equations　and　force　equilibrium　equations,　the　state　equation　of　Lamb　wave　propagation　in　plates　was　obtained.　Based　on　the　general　solution　of　state　equation　and　boundary　conditions,　the　dispersion　relation　and　modal　shapes　were　derived.　The　formulation　proposed　here　is　simple　and　can　be　easily　realized　by　program.　Finally　an　example　of　a　two　layers　MEE　plate　was　studied.　The　numerical　results　show　that　the　magneto-electro-elastic　coupling　changes　the　electrical　and　magnetic　potentials,　but　less　effects　on　the　dispersion　relation　and　elastic　displacements.