[ ${eta}$-Cryptoxanthin ] contents were determined from Citrus unshiu Markovich fruits grown in a greenhouse and open field of Jeju Island, off the southern coast of Korea. In a greenhouse and open field, the ${eta}$-cryptoxanthin content in the peel was greatly increased by harvesting citrus fruits in the late season from August through November. However, ${eta}$-cryptoxanthin content in the flesh was gradually increased and was superior to that of the citrus fruits grown in a greenhouse. ${eta}$-Cryptoxanthin was efficiently purified from the flesh of citrus fruits harvested in the late harvesting season in November. The ${eta}$-cryptoxanthin contents in the peel and flesh of citrus fruits harvested from a greenhouse in November were 0.89 mg% and 0.35 mg%, respectively, and in that obtained from an open field were 1.12 mg% and 0.35 mg%, respectively.