We investigated the taxonomic status of the Korean populations of Eurema hecabe (Linnaeus, 1758) based on morphology and nuclear triose phosphate isomerase (Tpi). Up to now, the Korean population of E. hecabe was classified into E. mandarina (de l''Orza, 1869) based on morphological characteristics. A previous study raised the possibility of the Jeju-do population to be E. hecabe based on the color of forewing’s fringe. However, morphological examination showed that the Korean population found in southern areas (Gyeonsang and Jeolla provinces), including Jeju-do is E. mandarina. In particular, the external morphology of autumn seasonal type of the Korean population was almost same as the Japanese mainland population, which is known as E. mandarina. Furthermore, sequence analysis of Tpi gene from nine individuals of E. mandarina collected in South Korean localities including Jeju-do clearly showed that all Korean specimens truly belong to E. mandarina.