Sasobit has been applied into asphalt successfully since 1997. From then on, a lot of studies emphasizes on how Sasobit can lower asphalt’s viscosity and reduce poison odor emission. However, the durability of asphalt containing Sasobit is ignored to research. This paper aimed to analyze Sasobit impact on the durability of asphalt. In this study, the Sasobit modified asphalt was blended using different Sasobit contents of 2%, 3%, 4% and 5% by weight of asphalt into the base asphalt (SBS modified asphalt). The Rolling Thin Film Oven test (RTFO) and Pressure Aging Vessel test (PAV) were conducted to simulate the mixing and construction aging and in-service aging of asphalt. The properties and micro-structure of the base asphalt and Sasobit modified asphalt in three different aging states (original state, mixing and construction aging state and in-service aging state) were tested by using the Penetration-Grade system, Performance-Grade system and fluorescence microscope. The aging indexes of the base asphalt and Sasobit modified asphalt were calculated to compare their durability. It was evident that the durability of the Sasobit modified asphalt was mostly affected by the type of base asphalt and Sasobit had a little impaction on the durability of the asphalt.