In this study, the influence of the micelles prepared by triblock copolymers on the properties of fresh and hardened cement paste was investigated.In fresh cement paste, the micelles adsorbed on cement particles and altered the zeta potential of partial cement particles, leading to a better workability.In hardened cement paste,the micelles retarded the hydration rate of C3S at the very early age but accelerated the hydration rate at the later age, resulting in a denser matrix and increased mechanical property.The most plausible mechanisms are related to the nucleation effect, molecular structure and adsorption performance of the micelles.