Abstract: Graphene oxide was modified with γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH-560) via a surface grafting method, followed by a reduction reaction with hydrazine hydrate to form functionalized graphene. The lowdensity polyethylene (PE-LD)based nanocomposite films were prepared by melt blending with functionalized graphene as well as the pristine one, followed by hollow blow molding, and their structures, morphologies, optical performance, and thermal and mechanical properties were characterized. The results indicated that the silane coupling agent, KH-560, was successfully grafted onto graphene. Compared to pristine graphene, the functionalized graphene exhibited an increase in disorder, and its interlayer space increased by approximately 80 %, which resulted in a better distribution in PE-LD matrix and a decrease in aggregation. Moreover, the thermal stability and mechanical properties of nanocomposite films were improved by functionalized graphene more significantly in comparison with pristine graphene. However, pristine graphene could enhance the optical and barrier properties more effectively. Compared to pure PE-LD films, the nanocomposite film containing 0.5 wt % of functionalized graphene presented an increase in crystallinity degree by 8.4 % and in Young's modulus by 63.9 %.