A concentration calculation system of an optically active substance, includes: a calculation unit configured to: acquire an amount of change in a polarization state by allowing light having different wavelengths to pass through a cornea and an aqueous humor and calculate a concentration of a specific optically active substance contained in the aqueous humor by a least squares method based on a theoretical formula which includes a matrix representing a polarization property of the cornea and a matrix representing a polarization property of the aqueous humor and represents a wavelength dependence of the amount of the change, wherein the matrix representing the polarization property of the aqueous humor is represented by a function of an expression representing the wavelength dependence of an optical rotation degree of the specific substance and the expression includes a concentration value of the specific substance as an unknown quantity or a temporal known quantity.
