Abstract: Core-shell PB-g-PS/asphalt is synthesized by grafting styrene and emulsified asphalt onto polybutadiene using the emulsion grafting/polymerizing technology. Then, the core-shell rubber particles are blended with asphalt to modify it with high-temperature storage stability provided. Some properties of the modified asphalt are investigated, such as the differences between the top and bottom layers of modified asphalt at the softening points due to high-temperature segregation, what the differential scanning calorimetric (DSC) analysis shows and the morphologies and homogeneous dispersion of rubber phases in the state of domain network structure In the modified asphalt the number of softening points increases obviously and the temperature difference due to segregation is lower than 1°C. The reaction between asphalt and core-shell rubber particle enables the components which are available to endothermic peak to shift to lower temperature with peak value decreased.