The effect of short-term and long-term oxidative ageing on the rheological, physical properties, the morphology, and thermodynamic behavior of the styrene-butadiene rubber (SBR)- and SBR/sulfur-modified asphalts is studied respectively. The dynamic rheological tests show the two major effects of ageing on the rheological behavior of the asphalt binders. Ageing prompts the degradation of polymer and increases the viscous behavior of the binders, on the other, ageing improves the elastic behavior of the binders due to the changed asphalt components, the final rheological behavior of the aged binders depends on the combined effect. The SBR/sulfur-modified asphalt is more susceptible to ageing and dynamic shear due to the structural instability and show a viscous behavior with increasing the sulfur level after ageing. Under the influence of repeated shear force, the high-temperature property of the SBR/sulfur-modified asphalts declines. The morphology observation shows the compatibility between polymer and asphalt is improved with further ageing especially for the SBR/sulfur-modified asphalt. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers