The present invention provides a multi layered air permeation preventive layer of pneumatic tires having −50 to −10i É of the steep decreasing range of the elastic modulus includes inner liner layer of a non-drawn film formed from a polymer composition including 60 to 90 wt. % of a thermoplastic resin and 10 to 40 wt. % of an elastomer, and carcass layer coated on the inside and outside of the inner liner layer, the tire thus manufacture has no fracture under a severe deformation during the tire shaping process, facilitating the tire manufacture, and exhibits an air permeation preventive property as an excellent air permeation preventive layer.