Studies on the polymerization of monosubstituted acetylenes with condensed aromatic rings are surveyed, and a new concept is demonstrated for designing acetylenic monomers to provide widely conjugated polymers with excellent solubility and stability. Monosubstituted acetylenes with condensed aromatic rings, which is designed to possess large steric hindrance between the pendant groups and main chain of the formed polymers, have been proven to give widely conjugated polymer backbones. W catalysts are advantageous for the production of polymers with high solubility and expanded main-chain conjugation, while Mo and Rh catalysts offer insoluble polymers with low degree of conjugation. Based on these results, a new substituted arylacetylene, anthrylacetylene with alkoxycarbonyl group (2), was subjected to polymerization to create a widely conjugated polymer with high molecular weight, excellent solubility and stability as well as film-forming ability.