An electrolyte composition is provided which is for use in a dye-sensitized solar cell that carries a dye on a semiconductor and converts light energy to electric energy by photoexcitation of the dye, and which comprises aluminum oxide and water, and has a paste-like form. By using the electrolyte composition for a dye-sensitized solar cell, the concern for liquid leakage can be eliminated, the operation cost and material cost can be reduced through simplification of an encapsulating step and increase in degree of freedom in selection of an encapsulating material, and besides the basic photoelectric conversion characteristics can be improved.