The　modal　loss　factor　of　cocured　laminated　composites　with　embedded　viscoelastic　layers　is　predicted　using　the　finite　element　based　modal　strain　energy　method　with　consideration　of　frequency　dependency　of　viscoelastic　materials.　The　contribution　of　energy　dissipation　of　fiber-reinforced　composites　to　the　loss　of　whole　system　is　taken　into　account　in　numerical　analysis　for　more　accurate　results.　Good　agreements　between　the　present　results　and　those　published　have　suggested　the　validity　of　the　proposed　approach.　The　effects　of　damping　of　fiber-reinforced　composites,　compliant　layering　and　location　of　damping　layers　on　the　loss　factor　of　damped　composite　beams　have　also　been　studied.　Some　ways　to　improve　damping　properties　of　cocured　laminated　composites　are　presented.