) In recent years, the use of polymer matrix nano composites to repair of bone defects and implant development is increasing; This is while the natural bone is detected as a nano composite with polymer matrix made by collagen and hydroxyapatite as reinforcements. Although, collagen- hydroxyapatite nano composite is the most similar nano composite to the bone, limitation of sources and methods providing collagen, and low strength of this nano composite limite its usage. Showing the bioactivity and better mechanical characteristics of nano forsterite than nano hydroxyapatite, polyethylene- forsterite nano composite is discussed as a replacement of collagen- hydroxyapatite nano composite while, polyethylene is an available polymer. The objective of present research was synthesis and characterization of polyethylene- forsterite nano composite. In this study, talc, magnesium carbonate and polyethylene(UHMWPE) were used as initial materials. First, the powder of talc and magnesium carbonate was mixed with specific fraction to manufacture of forsterite. Second, the manufactured forsterite was heated in 10 minutes at 1000°c. Afterwards, the manufactured forsterite in this way, was analysed with X Ray Diffraction(XRD) in order to observe the phase structure and (SEM) in order to observe the morphology and distribution of nano forsterite and bioactivation analysis for four weeks in (SBF) solution. The synthesized forsterite was mixed with polyethylene by mechanical milling and was transformed to nano composite with foure different volumes of forsterite by two ways, extrusion and press. The manufactured nano composites with these two ways, were analysed with (XRD) in order to observe the phase structure to endorse the existence of intent phases. In order to observe the morphology of nano composite and distribution of forsterite nano crystallite in polymer matrix, (SEM) was used. In order to analyse the bioactivity of nano composites, they were put in (SBF) solution for 28 days. After bioactivation analysis, they were analysed by XRD, SEM and EDX to identify the new productions and their morphology. Also, the nano composites manufactured by extrosion, were used for tensile examaination to analyse their mechanical characteristics and compare with bone and other polyethylene matrix nanocomposites with similar applications.