The electro-optical and electrochemical properties of poly(1-phenyl-2-trimethyl silylacetylene), which is a disubstituted polyacetylene with bulky phenyl and trimethylsilyl groups as substituents, were studied. The photoluminescence (PL) spectra of polymer showed that the photoluminescence peaks are located at 484 and 532 nm, corresponding to a photon energy of 2.56 and 2.33 eV, respectively. The cyclic voltamograms of the polymer exhibited reversible electrochemical behaviors between the doped and undoped peaks. It was found that the kinetics of the redox process of polymer is controlled by the reactant diffusion process.