A new methodology for preparation of polyquinolone was developed. Iterative nickel-catalyzed reaction of 6-alkynylisatoic anhydride monomer affords polyquinolone via decarboxylative cycloaddition without formation of residual by-product. It was demonstrated for the first time that decarboxylative cycloaddition can be an elementary process of chain growth polymerization for preparation of polyheterocycles with high regioregularity.