Building　trust　has　been　recognized　as　a　new　security　approach　for　wireless　distributed　networks.　In　the　paper,　we　try　to　provide　a　completely　new　view　by　building　trust　territory　in　ad　hoc　networks.　The　concept　of　trust　territory　is　addressed　and　the　approach　to　build　trust　territory　is　also　discussed.　A　trust　territory　contains　all　nodes　trusted　by　the　node.　It　is　considered　secure　to　communicate　with　nodes　in　the　trust　territories.　Theories　of　sets,　relations　and　graphs　help　to　build　trust　territories.　Trust　territory　could　work　in　all　layers　of　networks,　so　its　potential　for　future　applications　is　very　promising.