Aqueous two-phase systems (ATPS) are potential industrial techniques in the separation process of biomacromolecules, antibiotics, amino acids, and organic acids, etc. Partition behavior prediction of biomolecules in ATPS is an important problem. This paper applies the empirical protein partition model and the Florry-Huggins partition model to the experimental data of light-sensitive polymer P-NBC-dextran ATPS developed by our laboratory. It has been found that the Flory-Huggins partition model could comply with the experimental results, with an average relative error of 1.82 % and maximum relative error of 3.03 %.