The distributiion of Potamogeton alpinus Balbis which is the aquatic vascular plants was confirmed in Korea. We report the taxon as an unrecorded species in Korea. P. alpinus previously known as P. dentatus is characterized by unbranched stems and sessile, but not amplexicaul leaves with entire margins and obtuse apices. It differs from P. dentatus which has petiolated leaves with obtuse or round apex having mucronate tips.