Because　the　time　reversal　operator　of　Lamb　waves　varies　with　frequency　in　composite　structures,　the　reconstructed　signal　deviates　from　the　input　signal　even　in　undamaged　cases.　The　damage　index　captures　the　discrepancy　between　the　two　signals　without　differentiating　the　effects　of　time　reversal　operator　from　those　of　damage.　This　results　in　the　risk　of　false　alarm.　To　solve　this　issue,　a　modified　time　reversal　method　(MTRM)　is　proposed.　In　this　method,　the　frequency　dependence　of　the　time　reversal　operator　is　compensated　by　two　steps.　First,　an　amplitude　modulation　is　placed　on　the　input　signal,　which　is　related　to　the　excitability,　detectability,　and　attenuation　of　the　Lamb　wave　mode.　Second,　the　damage　index　is　redefined　to　measure　the　deviation　between　the　reconstructed　signal　and　the　modulated　input　signal.　This　could　indicate　the　presence　of　damage　with　better　performance.　An　experimental　investigation　is　then　conducted　on　a　carbon　fiber-reinforced　polymer　(CFRP)　laminate　to　illustrate　the　effectiveness　of　the　MTRM　for　identifying　damage.　The　results　show　that　the　MTRM　may　provide　a　promising　tool　for　health　monitoring　of　composite　structures.