The solubility data of L-arginine α-ketoglutarate (AAKG) were determined by the static gravimetric method from 283.15 to 323.15 K in 10 pure solvents (water, methanol, ethanol, isopropanol, acetone, acetonitrile, dichloromethane, ethyl acetate, 2-butanone, and 1,4-dioxane) and two water + ethanol and water + acetone binary solvent systems. According to the experimental results, their solubility positively correlated with the temperature. In the selected solvent systems, there was no polymorph found. In addition, the data analysis results showed that the polarity, hydrogen bond, Hildebrand solubility parameters, and molecular structure all affected the dissolution behavior. Four thermodynamic models including the modified Apelblat model, the λh model, the NRTL model, and the Apelblat−Jouyban−Acree model were used to correlate the solubility data.