The extraction and purification of limonin from pomelo seeds were studied.First,the effect of major single factors on the extraction of Pomelo was investigated.Then the extraction conditions were optimized by orthogonal experimental design.The optimum extraction conditions were: 70% ethanol concentration,70℃ of extraction temperature,2 hour of pretreatment,1:28 ratio of material and solvent.The best adsorption flow rate was 0.75 mL/min;the best elution flow rate was 0.5mL/min with 80% ethanol as eluting agent.