A nanocomposite composition having superior barrier properties and an article comprising the same are provided. The nanocomposite composition includes: a polyolefin resin; a nanocomposite having barrier properties, and including intercalated clay and one or more resins having barrier properties, and a compatibilizer. The resin having barrier properties comprises an ethylene-vinyl alcohol copolymer, a polyamide, an ionomer, a polyvinyl alcohol, or a combination comprising one or more of the foregoing resins. The nanocomposite composition has superior mechanical strength and can form a strong barrier to oxygen, organic solvent, and moisture. Also, the nanocomposite composition has superior chemical barrier properties and can be used in single/multi-layer blow molding and film processing.