Based　on　the　structural　characters　of　roof　in　fully　mechanized　top　coal　caving,　mechanical　analysis,　mechanical　calculation　and　simulation　experiment　were　used　to　explore　the　particularity　of　roof　structure　in　fully　mechanized　top　coal　caving.　The　simplified　model　of　roof　structure　was　built　in　final.　The　results　shown　that,　during　the　mining　by　fully　mechanized　top　coal　caving,　dynamic　balance　arch　structure　was　formed　by　the　roof　and　surrounding　rock　in　working　face.　in　the　same　time,　multi　span　beam　structure　was　formed　in　the　tendency　direction.　The　results　of　this　paper　would　provide　the　theory　basis　for　exploring　the　strata　behavior　regularity　in　further,　and　promote　the　safety　in　production　of　coal　mining　enterprises.　©　(2011)　Trans　Tech　Publications.