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($^{circ}$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 $^{circ}$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($^{circ}$Brix) of citrus juice showed highest statistical relationship(r=0.907) with total sugar, and was highly significant at 1% level.