There are provided a stabilized polyphenol solution which is applicable as various contact lens solutions and has high lens compatibility and safety, and further also a method for stabilizing such a polyphenol solution. At least one inorganic salt-free buffer is contained in a concentration of 0.001-5% by weight in an aqueous solution containing at least one polyphenol, at least one polyol is further contained therein in a concentration of 0.01-5% by weight to prepare a solution so as to contain no inorganic salt, and the pH of the solution is adjusted to 7.3 or less.
