The development and application of differential cap ply cord for radial tire were introduced. The performance of tire with bio-based polyamide 56（PA56） cap ply cord，polyethylene terephthalate（PET） cap ply cord and polyester PET/nylon66 hybrid cap ply cord and PET/bio-based PA56 hybrid cap ply cord was equivalent to that of tire with nylon 66 cap ply cord.The industrial application of these new differential cap ply cord materials for radial tires needs to be promoted by cord and tire manufacturers.With the diversification of market demand，there will be a new situation of coexistence and development of nylon 66 cap ply cord and a variety of differentiated cap ply cord for radial tire.
