Physicochemical properties affecting on the quality of Citrus unshiu Marc. var miyagawa and C. unshiu Marc. var, okitsu according to cultivation area in Cheju were investigated. Linear correlations (r>0.9) were showed between fruit size and peel thickness. There were much difference between cultivation areas in soluble solids of C. unshiu Marc. var. okitsu. The difference were not so much in soluble solids and acid contents of citrus fruits produced at same area below 65mm of fruit diameter, but the quality of large size fruits were inferior. Brix/Acid ratio could not be index for quality evaluation, because of individual deviation. Soluble solid content of citrus fruits produced in south Cheju was higher than that produced in north Cheju. Acid content and Brix/Acid ratio of citrus fruits produced in south Cheju was lower than that produced in north Cheju. The quality of C. unshiu Marc. var. miyagawa clad not so much difference between cultivation area, but the difference of quality were recognized significantly in C. unshiu Marc. var. okitsu.