Fano　coupling　between　Rayleigh　anomaly　and　localized　surface　plasmon　resonance　has　been　observed　in　diffractive　grating　structures　consisting　of　aluminum　nanolines　deposited　on　the　top　surface　of　photoresist　with　each　nanoline　composed　of　tightly　aggregated　aluminum　nanoparticles.　Localized　surface　plasmon　resonance　is　excited　both　in　the　nanoparticles　and　in　the　nanolines　by　differently　polarized　light.　The　surface　propagation　mode　excited　by　the　first-　and　second-order　Rayleigh　diffraction　anomaly　is　strongly　scattered　and　diffracted　by　the　plasmonic　aluminum　grating　structures,　producing　light　rays　in　the　same　direction　as　the　reflected　light　beam　with　the　same　spectral　feature　as　the　Rayleigh　anomaly.　The　narrow-band　diffracted　and　scattered　light　appears　as　sharp　dips　in　the　broad-band　reflective　optical　extinction　spectrum　of　plasmon　resonance,　which　is　recognized　as　a　kind　of　Fano　coupling.　This　kind　of　coupled　mode　is　utilized　successfully　in　refractive-index-sensor　devices　with　excellent　sensitivity.　(C)　2015　Elsevier　B.V.　All　rights　reserved.