The　purpose　of　this　study　was　to　investigate　how　the　addition　of　shrinkage-reducing　polycarboxylate　superplasticiser　(SRPC)　affected　the　shrinkage　of　cement-based　materials　(CBMs).　SRPCs　can　significantly　reduce　the　surface　tension　of　cement　solutions.　In　this　work,　a　new　molecular　structure　of　SRPC　was　synthesised;　its　surface　tension　was　reduced　to　34·1　mN/m,　which　is　lower　than　that　of　ordinary　polycarboxylate　superplasticisers　(PCEs).　Compared　with　mortars　without　additives,　the　shrinkage-reducing　ratios　of　mortars　containing　SRPC　at　7　and　49　d　were　about　33　and　22%,　respectively,　for　an　SRPC　dosage　of　0·2%　by　mass　of　cement.　The　results　showed　that　the　SRPC　reduced　the　shrinkage　of　CBMs　more　effectively　than　an　ordinary　PCE.　Furthermore,　the　shrinkage　mechanism　of　CBMs　containing　SRPC　was　assessed　regarding　three　aspects:　the　change　in　the　pore　size　distribution　of　the　cement　pastes　with　pore　size　below　50　nm,　the　reduction　of　the　capillary　pore　pressure　in　the　hardened　cement　pastes　after　the　addition　of　a　low-surface-tension　SRPC　and　the　reduction　in　the　evaporation　rate　of　moisture　through　SRPC　aggregation　on　the　gas-liquid　interface　in　cement　pastes.　©　2019　ICE　Publishing:　All　rights　reserved.