Abstract: The study aims to optimize the purification technology and parameters of macroporous resins to separate corosolic acid from Eriobotrya japonica leaves. Taking Eriobotrya japonica leaves as raw material, the content and purification of corosolic acid were analyzed by high performance liquid chromatography (HPLC), corosolic acid was extracted from loquat leaves by ethanol. Decolorizing was conducted with activated carbon and corosolic acid was separated by macroporous adsorptive resin. Results showed that the yield of corosolic acid was 7.76 mg/g. The optimum condition of decoloring with the activated carbon was: sodium hydroxide dosage of 0.2%, the activated carbon ratio of 1.5%, the temperature of 70℃ and the time of 20 minutes. 90% of pigment was eliminated, 91.2% of CA could be reclaimed. The results of macroporous resin separation static test showed that NKA9 resin was suitable for the separation, the static adsorption rate and desorption rate was 96.3% and 80.9%, respectively. The dynamic test indicated that the corosolic acid was separated by 90% ethanol, 7 BV of dosage and 3 BV/h of flow rate, 43.12% purity of corosolic acid was obtained.