A polymer electrolyte composition for a dye-sensitized solar cell, a polymer electrolyte, a dye-sensitized solar cell employing the polymer electrolyte, and a method for preparing the same. The polymer electrolyte composition for a dye-sensitized solar cell includes: a mono-functional or multi-functional monomer having at least one ethylene glycol in a side chain; a photoinitiator; a lithium salt; and an organic solvent. The polymer electrolyte suppresses the volatilization of a redox electrolyte and provides stable photoelectrochemical properties against environmental changes, such as a rise in the external temperature of a solar cell. The dye-sensitized solar cell includes: first and second electrodes facing each other; a dye-adsorbed porous film interposed between the first and second electrodes; and the polymer electrolyte interposed between the first and second electrodes. The dye-sensitized solar cell has a high voltage and high photoelectric conversion efficiency.