The　effects　of　loading　frequency,　temperature　and　multi-walled　carbon　nanotubes　(MWCNTs)　on　the　energy　dissipation　property　of　cement　paste　were　explored　in　the　paper.　Energy　dissipation　was　characterized　by　loss　factor　(defined　as　loss　modulus　/storage　modulus　E　&　DPRIME;/E　&　PRIME;),　and　the　roles　of　MWCNTs　were　analyzed　emphatically　by　micro　tests.　The　energy　dissipation　of　cement　paste　originated　from　the　sliding　of　C-S-H　sheets　at　nanoscale　and　the　friction　of　C-S-H　globules　at　microscale.　The　loss　factor　decreased　with　the　increase　of　loading　frequency　and　temperature.　After　analyzing　the　micro　tests　results　such　as　nuclear　magnetic　resonance　and　atomic　force　microscope,　the　mechanism　of　MWCNTs　enhancing　the　energy　dissipation　property　of　cement　paste　was　pro-posed:　(1)　at　nanoscale,　the　mean　chain　length　of　C-S-H　was　increased　by　MWCNTs,　leading　to　the　sliding　area　of　C-S-H　sheets　larger　and　increasing　energy　dissipation;　(2)　at　microscale,　the　morphology　of　C-S-H　gradually　changed　from　globules　to　foil　due　to　the　presence　of　MWCNTs,　which　increased　the　friction　area　and　the　energy　dissipation　was　enhanced;　(3)　MWCNTs　were　fibrous　and　bonded　with　C-S-H,　and　the　friction　between　the　their　interfaces　dissipated　energy　under　alternating　stress;　(4)　the　small　pore　volume　and　pore　roughness　were　increased　by　MWCNTs,　which　were　contributed　to　increase　the　energy　dissipation.