Propagation　characteristics　of　longitudinal　modes　in　pipes　with　viscoelastic　coatings　are　analyzed　theoretically.　Dispersion　and　attenuation　characteristics　of　longitudinal　modes,　especially　L(0,　2)　mode,　are　studied.　Excitation　and　reception　of　L(0,　2)　mode　in　a　steel　pipe　coated　with　epoxy　are　carried　out　in　the　experiment.　With　increasing　frequency,　the　effect　of　the　layer　of　epoxy　on　propagation　characteristics　and　the　attenuation　of　L(0,　2)　mode　in　low　frequency　range　increases.　Results　show　that　attenuation　dispersion　curves　can　provide　theoretical　guidance　for　mode　selection　when　longitudinal　modes　are　used　for　defect　detection　in　pipes　with　viscoelastic　coatings.