The miscibility of Nylon-f/12 or Nylon-12 with ethylene-vinylalcohol copolymers of various vinylalcohol content was studied from scanning electron microscopy, thermal properties, and crystallization kinetics. Nylon-6/12 or Nylon-12 has good miscibility with ethylene-vinylalcohol copolymer which is composed of 33mo1% vinylalcohol, and has partial miscibility with ethylene-vinylalcohol copolymers which are composed of 71, 62, or 18mol% vinylalcohol. These results are interpreted qualitatively as the miscilility is increased as the difference of solubility parameters of Nylon and ethylene-vinylalcohol copolymer is decreased.