Crumb rubber pretreatment by microwave irradiation before blending with an asphalt matrix improves the properties of rubber-asphalt blends. This treatment cleft the surface vulcanization network, resulting in higher surface activity of the crumb rubber and improved compatibility with asphalt. This new rubber blend exhibited minor temperature susceptibility behaviors and high ductility at 5 ı C and an improved viscoelastic nature and storage stability. Characterization has also been performed to elucidate the mechanism for this improvement using a microwave treatment technique.