The solubility of folic acid in water was measured at pH values between 0 and 7 at the temperatures (298.15, 303.15, and 313.15) K using a standard shake and settle method with analysis by high-performance liquid chromatography (HPLC). A temperature and dissociation constant related solubility model was built to describe the folic acid solubility performance, and the experimental data matched the model well with a square of the multiple correlation coefficient (R(2)) of 0.9900.