A　novel　star-shaped　polycarboxylate　superplasticizer　(SPCE)　was　synthesized　through　a　simple　two-step　method.　H-1　Nuclear　Magnetic　Resonance　(H-1　NMR)　and　Infrared　Spectroscopy　(IR)　measurements　were　used　for　structural　characterization.　SPCE　and　comb-shaped　polycarboxylate　superplasticizer　(CPCE)　with　same　molecular　weights　were　designed　and　synthesized.　The　cement　paste　containing　SPCE　exhibited　better　fluidity,　fluidity　retention,　water　reduction,　25%　lower　saturated　dosage　of　PCE,　10%　longer　setting　time,　lower　hydration　heat,　more　delayed　hydration　heat　evolution　and　lower　amount　of　hydration　products　at　early　ages.　Furthermore,　the　adsorption　behavior　of　SPCE　and　CPCE　in　cement　pastes　and　the　zeta　potential　were　investigated,　and　then　the　working　mechanism　of　SPCE　was　theoretically　explained.　It　is　interesting　that　changing　topological　structure　from　comb-shape　to　star-shape　can　achieve　the　optimization　of　dispersion　effect,　and　further　improve　the　working　effectiveness.　The　aims　of　this　study　are　to　provide　a　new　avenue　to　synthesize　superplasticizer　with　novel　structure　achieving　the　chemical　diversity　of　superplasticizer　structure,　and　to　verify　the　contribution　of　optimizing　molecular　shape.　This　new　type　of　superplasticizer　can　be　used　as　a　rheology　modifying　agent　in　fresh　cement-based　materials.　(C)　2017　Elsevier　Inc.　All　rights　reserved.