The electroluminescence of J-aggregates was detected in polymer systems doped with cyanine dye molecules. J-aggregate/polymer composites exhibiting intense absorption band with a maximum in the red range were developed on the base of polyimides and a copolymer formed from phenylacetylene and 4-methylcoumarin-4-pentynoate. Efficient electrolumunescence was revealed in these systems. It was found out that J-aggregates play an active role in charge carrier transport in the composite materials.