Physico-chemical components which are closely related to processed products were investigated on 10 varieties of Cheju citrus fruits. Juice ratio of Hungjin was the highest, 49.2%, while Sankyool was the lowest, 4.2%, which showed great differences among varieties. Peel ratio of Dangyooja was the highest, 46.1%, while both Navel orange and Hungjin were relatively low. Soluble solid(Brix) was relatively high In Sankyool, Meiwa Kumquat, Sambokam and Iyo. Acid content was the highest, 4.86% in sudachi and relatively high in Sankyool, Natsudaidai and Dangyooja. The Brix to acid content ratio was 13.9 in Meiwa Kumquat and more than 10 in Navel orange and Hungjin. Total sugar contents of Juice were 2.78∼10.94%, while reduced sugar contents were 1.63∼6.38% which showed higher in Meiwa Kumquat, Iyo and Navel Orange. Hesperidin and naringin, the sources of biiter taste and cloudness were low in Hungjin and Iyo. Soluble solid(Brix) of citrus juice showed highest statistical relationship(r=0.907) with total sugar, and was highly significant at 1% level.