The graphene oxide(GO) was prepared by modified Hummers method. The shear stress of the fresh alkali activated slag paste(AASP) with GO was measured by rotary viscometer, and the rheological parameters of the obtained paste was calculated based on Herschel Bulkley(H B) model. Results show that GO reduce the thixotropic properties and increased the stability of the fresh AASP. With GO content(by mass, the same below) increased from 001% to 005%, the yield stress and consistency coefficient of fresh AASP increase, while the fluidity reduce. At the same time, hysteresis loop area and rheological index decrease with the increase of GO content, and GO decrease the thixotropic properties of the paste. A mechanism for the effect of GO on the rheological properties is proposed, which specifically explained as GO and slag particles are chemically bonded to form flocculation structures. Furthermore, the flocculation structures increase with the increase of GO content with the result that the rheological properties of the paste changed. The fluidity of AASP containing 003% GO is increased from 180mm to 203mm by incorporating 15% FDN, which indicated that the addition of FDN can increase the fluidity of GO AASP.