In recent years, blooming construction of megaprojects has posed higher performance demand for cementitious materials. Nanoscience and nanomaterials are advisable approach to improve the performance of cementitious materials from a microscopic perspective. Recently, researchers has made significant progresses in applying nanomaterials such as nano silica, nano calcium carbonate, carbon nanotube and grapheme in cementitious systems. Present research progress has shown that nanomaterials improve cement&concrete performance through three aspects: hydration acceleration, hydration product optimization and microstructure refinement. Considering the degree of performance optimization, the application potential of nanomaterials is applausible. However, the dispersion problem of nanomaterials has to be further solved and commercialized dispersion technique should be proposed. Moreover, structural modification of nanomaterials for construction is still to be further explored.