The ionic polyacetylenes have potentials as materials for mixed ionic and electronic conductivity, energy storage devices such as batteries, permselective membrane, light-emitting devices. Here, an ionic polyacetylene, poly(3-ethynyl-N-pentylpyridinium iodide), was synthesized by the non-catalyst polymerization of 3-ethynylpyridine using 1-iodopentane. The kinetics of the polymer redox process was found to be mainly controlled by the reactant diffusion process from the experiment of the oxidation current density of polymer versus the scan rate. The photoluminescence maximum peak of polymer was located at 534 nm, which corresponds to the photon energy of 2.32 eV.