Theoretical　model　and　experimental　research　is　carried　out　on　material　elastic　constants　inversion　method　of　coating　plates　by　acoustic　non-destructive　test.　Taking　advantage　of　the　broadband　line　focus　transducer　and　the　precise　ultrasonic　nondestructive　detection　system　established　on　our　own,　obtained　the　acoustic　characterization　of　thin　coating　structure.　A　great　amount　of　data　(601　groups)　of　pulse-echo　signals　are　acquired　in　an　accurate　defocusing　interval　(20　μm).　V(f,　z)　analytical　method　is　applied　on　the　extraction　of　measured　dispersion　curves　for　coating　sheets.　Associated　with　the　theoretical　analysis　of　wave　propagation　of　coating　materials,　a　computation　model　of　theoretical　dispersion　curves　is　established.　Comparing　the　experimental　data　with　the　theoretical　curves,　the　acoustic　wave　velocities　are　obtained　by　curve-fitting　method,　and　finally　the　inversion　of　elastic　constants,　e.g.　Young＇s　modulus　and　Poisson＇s　ratio,　are　achieved.　The　experimental　results　agree　well　with　the　theoretical　ones,　while　it　shows　that　the　inversion　method　is　feasible　and　reliable.　This　research　laid　the　foundation　of　non-destructive　evaluation　of　mechanical　properties　of　coating　materials.　©　2014　Journal　of　Mechanical　Engineering.