Abstract: In recent years, nanomaterials have led to promising developments in the improvement of pavement performances. In this study, nanosilica was added to LLDPE polymer modified binder at concentration of 1-6% by weight of bitumen binder. Characteristics of nanocomposite modified binders were evaluated using conventional and Superpave binder test techniques. Penetration test, softening point test, Dynamic Shear Rheometer (DSR) and Rolling Thin Film Oven Test (RTFOT) were used to analyze performance and rheological properties of the nanocomposite modified binders. In addition, the aging resistance of nanocomposite modified binders after RTFOT short term aging was evaluated through aging indices. The results show that, nanosilica content has significant effect on polymer modified binder. Nanosilica composite modified binders penetration decreases and softening point increases with increase in nanosilica, this implies enhancement in binders hardness and stiffness. RTFOT aging indices evaluations show that, nanosilica composite modified binders achieved the minimum superpave requirements; this implies that nanosilica reduces oxidative aging. The overall findings show that, nanosilica protects the polyethylene polymer modified binder from binder from oxidative aging.