Solid-state polymerization of 4,4'-butadiynedibenzylammonium disorbate was investigated. The quantitative polymer yield of the diene moieties was achieved under UV-, X-ray, and gamma-ray irradiation, whereas the conversion of diyne moieties was low. X-ray crystal structure analyses of monomer and polymer crystals show the polymerization proceeded under topochemical polymerization mechanism indeed.