A　compression　test　is　performed　to　investigate　the　effects　of　carbon　nanotubes　(CNTs)　on　twin　and　texture　evolution　of　the　1.0　wt.%　CNTs　reinforced　magnesium　matrix　(CNTs/Mg)　composite.　The　compression　process　consists　of　elastic,　yield　and　hardening　stages,　and　the　number　of　twin　significantly　increases　at　the　yield　stage.　During　the　compression　process,　the　crystal　rotation　and　non-basal　slip　caused　by　twin　shear　alternately　dominate　the　deformation　of　the　1.0　wt.%　CNTs/Mg　composite.　The　CNTs　existing　at　grain　boundaries　lead　to　stress　concentration,　and　the　stress　concentration　stimulates　the　formation　of　twins　at　the　yield　stage.　The　formed　twins　interact　with　dislocations,　result　in　crystal　rotation　and　promotion　of　the　non-basal　slip　system　at　the　hardening　stage　under　the　effect　of　twin　shear,　thus,　improve　the　toughness　of　the　CNTs/Mg　composite.