Abstract: An adhesive composition for adhering an organic synthetic fiber to a nitrile group-containing highly saturated copolymer rubber, said composition comprising a nitrile group-containing highly saturated copolymer rubber latex having an iodine value of not more than 120 and a resorcinol-formaldehyde resin, characterized in that the nitrile group-containing highly saturated copolymer rubber latex is obtained by treating a nitrile group-containing unsaturated copolymer rubber latex resulting from emulsion polymerization with hydrogen in the presence of a hydrogenation catalyst to selectively hydrogenate a carbon-carbon double bond of the nitrile group-containing unsaturated copolymer constituting said latex.