Abstract: The distribution behavior of alpha-ketoglutarate in aqueous two-phase systems containing low molecular organic solvent and inorganic salt was studied. Double beam ultraviolet-visible spectrophotometer was used for the qualitative and quantitative determination of alpha-ketoglutarate.The best absorption wavelength was 235.14 nm and the standard curve was C=1.8239A+0.0128(R²=0.999) in range of 0.005~0.250(g/L). In this experiment, a new aqueous two-phase system contained hydrophilic organic solvent acetone and dipotassium hydrogen phosphate was adopted. The effects of acetone dosage,dipotassium hydrogen phosphate dosage and extraction temperature on the distribution of alpha-ketoglutarate in two phases were studied. The optimum technological conditions were determined:the system total amount was 40 g, acetone dosage was 9.6 g, dipotassium hydrogen phosphate dosage was 6 g, extraction temperature was 30℃. In this condition, the allocation coefficient of alpha-ketoglutaric acid was K=2.5, and the extraction rate was E=87.56%.