A non-aqueous electrolytic solution composed of two or more organic compounds
dissolved
in a solvent composed of a cyclic carbonate and a chain carbonate, in an amount
of 0.01 to 8 weight % for each compound, in which both of the two organic compounds
have a reduction potential higher than those of the cyclic and chain carbonates,
and in which one of the organic compounds has a reduction potential equal to that
of another organic compound or has a reduction potential lower or higher than that
of another organic compound by a potential of less than 0.4 V is favorably employable
for a non-aqueous secondary battery.