Polycarboxylate　ether　(PCE)　superplasticizers　are　widely　used　in　concrete,　but　in　some　cases,　PCE　aggravates　the　occurrence　of　cracks.　This　study　evaluates　the　shrinkage　reduction　and　plasticizing　properties　of　a　newly　synthesized　shrink-reducing　polycarboxylate　polymer　(KH-SRPC)　modified　with　ester　and　silane　groups.　When　the　KH-SRPC　was　implemented　at　a　dosage　of　0.3%　by　weight　of　cement,　the　adsorption　capacity　on　the　surface　of　the　cement　particles　and　the　spreading　diameter　of　the　cement　improved　with　respect　to　traditional　PCE.　Furthermore,　the　autogenous　shrinkage　and　drying　shrinkage　of　the　mortar　containing　KH-SRPC　were　also　investigated.　When　the　KH-SRPC　content　was　0.2%　of　the　weight　of　the　cementitious　material,　the　autogenous　shrinkage　of　the　KH-SRPC　mortars　at　3　and　7　days　was　reduced　by　72.6%　and　43.5%,　respectively.　The　drying　shrinkage　of　KH-SRPC　mortars　decreased　by　38.3%　at　3　days,　39.0%　at　7　days,　39.1%　at　14　days,　and　35.7%　at　28　days.　It　was　found　that　KH-SRPC　changed　the　pore　structure　of　the　solidified　mortar,　reduced　the　surface　tension　of　the　pore　solution,　and　slowed　down　the　rate　of　hydration,　thereby　reducing　the　total　shrinkage　of　the　mortar　system.