Provided is a resin composition comprising 1-99% by weight of a modified ethylene-vinyl alcohol copolymer (C) having an ethylene content of 5-55 mol %, which contains a specific structural unit (I) in an amount of 0.3-40 mol % and can be obtained by reacting an ethylene-vinyl alcohol copolymer (A) with a monofunctional epoxy compound (B) having a molecular weight of not more than 500, and 1-99% by weight of a thermoplastic resin (T1) other than (C). Moreover, a multilayer structure in which the resin composition and a thermoplastic resin (T2) are laminated is also provided. Thus, a resin composition superior in barrier properties, transparency, stretchability, flexibility, flexing resistance and interlayer adhesiveness and various kinds of molded articles made thereof are provided.