Nanomaterials possess many special physical and chemical properties based on small size, surface and interface effects. The use of nanomaterials, as additives, will provide a well bonded interface that will enable polymer based nano composites to exhibit higher performance. Higher performance is very much influenced by various techniques of preparation of nanocomposite. Melt mixing technique involving a co-rotating intermeshing twin screw extruder for preparation of nanocomposite is an effective processing method and can play an important role in preparation of nanocomposite with uniform mircostructure. Currently, there is considerable interest in ultra high molecular weight polyethylene (UHMWPE) because of their superior abrasion resistance, reduced coefficient of friction, enhanced work of fracture and improved moisture barrier. The UHMWPE/HDPE blend has drawn much attention as a promising human joint repair material because such a blend has higher wear resistance than neat UHMWPE. Keeping these advantages in mind, attempts have been made to fabricate composites of UHMWPE blended with HDPE and nano fillers of Copper with various weight percentages viz.(i)0.1%, (ii)0.5%, (iii)1.0% and 5.0%. The composites have been prepared by melt mixing process and various properties such as (i) Microstructure (ii) Tribological (iii) Thermal and (iv) Mechanical have been evaluated. The paper compares these properties of nanocomposites with neat unfilled UHMWPE/HDPE blend.