To compare the efficiency of sprinkler and drip irrigation systems for potato cultivation in the subtropical area, potato was irrigated with two different systems in the dark brown non-volcanic soil. Potatoes were planted perpendicular to the sprinkler line-sources on the ridges and planted parallel to the drip line on 3 ridges by automatic irrigation system. Quantity of applied water through the sprinkler system were 323, 328, 335, 348 and 357 mm as measured by the catch-can installed above the center of the canopy. Amounts of water irrigated by the drip system were 330, 337, 344 and 351mm, Those amounts were equivalent to those of precipitation from Feb. 10 to Jul. 9 in the experimental sites of Cheju Island. Yields of potato were increased with increasing amount of applied water in sprinkler plots, but those in drip plots were not in proportional to the irrigation amounts. Efficiencies of water usage for 1kg of potato production were 119 - 160 kg with sprinkler, 57 - 100 kg with drip system, respectively.