Thinfilmsofpolymerblendscomposedofalternatingcopolymer,diblockcopolymerand/orhomopolymerarestudiedusingMonteCarlosimulation.Amultilayermorphologyisobservedinthefilm,thatis,theblendedpolymersassembleintoinpidualdomainsarrangedfrominteriortothesurfacesofthefilm.Thecoexistingcomponentsresidingthroughouttheneighboringdomainsinthefilmmakenodistinguishableinterfacebetweenanyneighboringdomains.Bythismeans,itformsaverticalcompositiongradientinthepolymericfilm.Beingdifferentfromlayer-by-layerdepositionofpolyelectrolyteorhydrogenbondingapproachetc.,thelayeredstructureinthisstudyisformedbypolymerblendinginonestep.Alternatingcopolymersarefoundtobeessentialcomponentstoformverticalcompositiongradient(layeredstructure)inthinfilms.