A　super　carbon　nanotube　(SCNT)　is　a　cylinder　rolled　up　from　a　super　graphene　(SG)　layer　which　is　built　by　connecting　Y-type　single　walled　carbon　nanotube　(SWCNT)　junctions.　The　unique　structure　of　the　SCNT　results　in　two　determinants　of　radius　of　the　SCNT,　the　number　of　junctions　along　the　circumferential　direction　of　the　SCNT　and　length　of　the　constituent　SWCNTs.　The　mechanical　behaviors　of　the　SCNTs　are　investigated　by　using　a　generalized　molecular　structure　mechanics　(MSMs)　method　which　is　generated　by　combining　the　MSM　method　with　the　failure　criterion　of　the　carbon-carbon　bonds.　The　results　show　that　number　of　junctions　along　the　circumferential　direction　of　the　SCNTs　and　length　of　the　constituent　SWCNTs　both　have　obvious　effect　on　deformation　process　of　the　SCNTs.　Moreover,　the　size-and　shape-dependence　of　the　Young＇s　modulus　and　Poisson＇s　ratio　of　the　SCNTs　are　calculated　by　the　generalized　MSM　method.　Exact　relations　between　the　mechanical　properties　of　the　SCNTs　and　their　size　which　can　reasonably　fit　the　computed　results　are　provided.　(C)　2012　Elsevier　B.V.　All　rights　reserved.