Excited　modes　and　frequency　response　are　two　key　parameters　of　ultrasonic　guided　wave　transducers　evaluating.　However,　traditional　transducers　such　as　piezoelectric　transducer　and　electromagnetic　acoustic　transducer　(EMAT)　can＇t　measure　these　two　parameters　efficiently　because　of　the　limit　of　frequency　bandwidth　and　mode　selection　of　themselves.　Laser　vibrometer　can　be　employed　to　measure　the　raw　in-plane　and　out-of-plane　displacement　of　elastic　waves　in　the　structure　without　the　limit　of　bandwidth.　Thus　it　could　be　one　of　the　ideal　methods　to　identity　the　excited　modes　and　measure　the　frequency　response　curve.　A　kind　of　omnidirectional　lamb　wave　EMAT　is　been　inspected　by　this　method.　The　results　show　that　the　transducer　can　produce　purity　S0　mode　in　150~200　kHz　and　both　A0　and　S0　mode　in　50~150　kHz.　It　can　be　predicted　that　the　method　using　laser　vibrometer　to　detect　the　in-plane　and　out-of-plane　displacement　is　an　efficient　method　of　evaluating　the　transducer　and　receiving　Lamb　waves,　and　can　be　widely　used　in　no-contact　measurement,　high　temperature　testing　and　3D　visualization　of　elastic　waves　propagation.　©2012　Journal　of　Mechanical　Engineering.