Aiming　at　wide　range　health　monitoring　of　plate　structure,　an　omni-directional　Lamb　wave　electromagnetic　acoustic　transducer　(EMAT)　was　developed.　Based　on　the　theory　of　electromagnetic　acoustic　testing,　the　model　of　omni-directional　Lamb　wave　EMAT　for　plate　was　established,　and　the　expressions　of　received　signal　and　equivalent　sensitivity　were　obtained.　Considering　the　relationship　between　structural　parameters　of　EMAT　and　its　equivalent　sensitivity,　seven　omni-directional　EMATs　were　fabricated,　and　their　impedance　matching　was　conducted.　Experiment　and　theoretical　analysis　show　that　the　designed　EMAT　can　excite　single　S0　mode　Lamb　wave　effectively　and　has　selectivity　to　the　lamb　wave　with　given　wavelength,　and　the　tested　center　frequency　agrees　well　with　the　designed　value.　Meanwhile,　the　measured　sensitivities　of　EMATs　with　different　ratios　of　inner　and　outer　diameters　are　consistent　well　with　the　theoretical　curves　at　same　frequency.　Experiment　results　prove　that　the　designed　EMATs　have　good　consistency　in　the　direction　of　360°,　which　establishes　a　good　foundation　for　the　development　of　subsequent　transducer　array　for　plate　structure　monitoring.