A novel organic/inorganic nanocomposite of polyethylene (PE) was prepared via in-situ coordination polymerization. The Ziegler-Natta catalyst was first supported on the surface of silicate nanowhiskers to subsequently initiate the polymerization of ethylene on the surface of these nanowhiskers. The nanowhiskers were encapsulated by polyethylene and became reinforcements fibers of the composite. The strong interaction between the uniformly dispersed nanowhiskers and the resin matrix resulted in the formation of a kind of organic/inorganic network providing good mechanical properties.