With　the　development　of　computer　science　and　technology,　current　secure　operating　systems　failed　to　respond　to　many　new　security　challenges.　Trusted　operating　system　(TOS)　is　proposed　to　try　to　solve　these　problems.　However,　there　are　no　mature,　unified　architectures　for　the　TOS　yet,　since　most　of　them　cannot　make　clear　of　the　relationship　between　security　mechanism　and　the　trusted　mechanism.　Therefore,　this　paper　proposes　a　double-system　architecture　(DSA)　for　the　TOS　to　solve　the　problem.　The　DSA　is　composed　of　the　Trusted　System　(TS)　and　the　Security　System　(SS).　We　constructed　the　TS　by　establishing　a　trusted　environment　and　realized　related　SS.　Furthermore,　we　proposed　the　Trusted　Information　Channel　(TIC)　to　protect　the　information　flow　between　TS　and　SS.　In　a　word,　the　double-system　architecture　we　proposed　can　provide　reliable　protection　for　the　OS　through　the　SS　with　the　supports　provided　by　the　TS.　(C)　2011　Published　by　Elsevier　B.V.　Selection　and/or　peer-review　under　responsibility　of　Garry　Lee