Maleated polyethylene composites with different aspect ratios of clays and SiO2 were prepared by melt compounding. Aspect ratio of clay affects significantly the physical and mechanical properties of a nanocomposite. The composite with the highest aspect ratio of clay (Closite 20A) shows the higher storage modulus, complex viscosity, the higher melt tension of polymer and the longer drawability and lower neck-in during the melt processing than those with the low aspect ratio clay (SCPX2231) and SiO2. It also shows an easy orientation in the polymer in melt drawing direction.