Abstract: A linear random N-substituted acrylamide copolymer comprising 65 to 99% by mole of ethylene units, 1 to 15% by mole of acrylate units and 1 to 35% by mole of acrylamide units, the copolymer having a weight average molecular weight of 1000 to 50000, and an aqueous composition, a resin film, a laminate, recording paper and a foamed article comprising the N-substituted acrylamide copolymer, respectively. The N-substituted acrylamide copolymer is excellent in antistatic ability for thermoplastic resins and does not lower physical properties such as transparency and elongation of films and articles which are formed from a thermoplastic resin. Moreover, the N-substituted acrylamide copolymer is excellent in anti-blocking ability so that the copolymer can be suitably used for various uses.