Relative　humidity　(RH)　has　an　important　influence　on　the　creep　performance　of　cement-based　materials.　In　this　paper,　the　creep　and　creep　recovery　experiments　of　hardened　cement　paste　(HCP)　were　carried　on　under　four　humidity　balance.　The　low-field　1H　nuclear　magnetic　resonance　(NMR)　test　was　performed　on　the　HCP　after　the　creep　recovery　test　to　obtain　the　internal　water　distribution　characteristics　of　HCP.　The　creep　properties　and　volume　ratio　of　different　micro　phases　in　HCP　were　acquired　by　nanoindentation　test,　backscattered　electron　(BSE)　test,　and　thermogravimetric　(TG)　test.　Subsequently,　the　structure　features　of　C–S–H　were　acquired　by　the　29Si　NMR　test　and　the　nitrogen　adsorption-desorption　test.　The　results　showed　that　the　raise　of　RH　significantly　increased　the　interlayer　water　content　in　HCP.　The　creep　properties　of　C–S–H　reduced　significantly　with　the　increase　of　RH.　The　volume　fraction　of　low-density　(LD)　C–S–H　elevated　with　raising　RH,　while　the　trend　of　high-density　(HD)　C–S–H　was　opposite　to　the　former.　When　RH　increased,　the　mean　chain　length　of　the　gel　raised,　and　the　gel　pores　became　more　numerous,　among　which　the　magnitude　of　change　of　LD　C–S–H　pores　was　more　significant.　©　2023　Elsevier　Ltd