Abstract:With the low-temperature baked navel orange peel as material，the limonin was extracted from the navel orange peel by the aqueous two-phase system of ethanol-（NH4）2SO4. The influence of the temperature on the chromogenic property of limonin was studied by spectrophotometric method，and the optimal chromogenic temperature was 30℃. On the basis，the standard curves on the limonin was established，and the effects of ethanol concentration，solid-liquid ratio，amount of the ammonium sulfate，extraction temperature and extraction time on the extraction rate were studied by the single factor experiments and the orthogonal tests. The results showed that when the volume concentration of alcohol was 60 %，the solid-liquid ratio was 1∶20（g/mL），the amount of the ammonium sulfate was 12 g，the extraction temperature was 50℃and the extraction time was 4 h，the extraction rate reached the maximum. Under the optimum conditions，five parallel experiments were carried out and the average extraction rate reached 0.345 3 %. The reproducibility of the experiments was good.