An ionic polyacetylene with 4-nitrobenzenesulfonyl substituents was easily prepared via the non-catalyst polymerization of 2-ethynylpyridine using 4-nitrobenzenesulfonyl chloride. The polymerization proceeded in homogeneous manner to give a moderate yield of polymer (65 %). The polymer structure was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed N-(4-nitrobenzenesulfonyl)pyridinium chloride. The photoluminescence peak was observed at 584nm corresponding to a photon energy of 2.12eV although it is weak due to nitro group. Based on absorption spectrum, band gap was 2.16eV. The cyclic voltammograms of polymer exhibited the electrochemically stable window at the -1.8 approximate to 1.50V region. Oxidation and reduction were started at 0.43 and -0.9V and had stable electrochemical property up to 30 cycles.