Some echinoids were collected from the coast of Gangwon-do during the period from November 2008 to July 2011 and were identified on the basis of morphological characteristics and molecular analysis of cytochrome oxidase subunit I mitochondrial DNA. Among them, Strongylocentrotus pallidus (Sars, 1871) belonging to the family Strongylocentrotidae of the order Camarodonta is reported for the first time in Korea and is redescribed. The genetic differences ranged from 0.038 to 0.139 between S. pallidus and four other species of genus Strongylocentrotus, but ranged from 0.002 to 0.005 between Korean specimens and GenBank data of S. pallidus. This species is widely distributed in cold sea water along the western part of the North Pacific and the Northwest Atlantic.