To obtain a polyquinoline which can be cured without using any catalyst, which polyquinoline comprises repeating quinoline units and has acetylene functional terminals.

This polyquinoline has a structure of, for example, E"-(PQ)x-E". In the formula, (PQ)x is a polymer chain containing repeating quinoline units; (x) is 1-100,000; E" is -C≡CR, -Ar-C≡R, or -CH2C≡CR (wherein R is H, an alkyl, an aryl, or a heteroaryl; and Ar is an arylene or a heteroarylene). This polyquinoline can be used as a film when case or as a coating film when applied to a substrate. By heating it to a desired degree after casting or application, a thermoset polymer excellent in heat resistance and solvent resistance can be obtained. The polyquinoline has a wide tolerance of processing and a difference of 50°C or above between the glass transition temperature or the melting temperature and the curing temperature.