Influences of perfluorooctyltriethoxysilane（PFOTES） on the workability， anti-icing performance and microscopic properties of cementitious materials were studied.The chemical composition and physical phases of the cement hydration products were also investigated by thermogravimetric-differential scanning calorimeter（TG-DSC） and X-ray diffractometer（XRD）. The results show that the incorporation of PFOTES can prolong the setting time of cement paste. The impacts of low PFOTES content to the reduction of ice adhesion and increase of contact angle are more significant, and both ice adhesion and contact angle remain basically the same with further increase of PFOTES content. With PFOTES， the water absorption of the modified mortar reduces， the compressive strength decreases and the porosity increases. It is proved by microscopic tests that PFOTES delays the hydration of cement but does not produce new hydration products.