Based on a large quantity of fossil material and more detailed description of the morphological features, two Cypridea species are recognized from the Jinju Formation of the Gyeongsang Basin: Cypridea jinjuria Choi, 1990 and Cypridea samesi n. sp. These two species do not co-occur and are endemic to South Korea. However, they share the same morphological feature, a swelling/node-like swelling at the anterior cardinal angle area, with some other Cypridea species from the Lower Cretaceous sediments of China and Mongolia. This may suggest a close relationship between these species. Paleobiologically, we infer a parthenogenetic reproduction mode for Cypridea jinjuria Choi, 1990 and Cypridea samesi n. sp., and suggest that the Jinju Formation was deposited under conditions with long hydroperiods. (C) 2018 Elsevier Ireland Ltd Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier B.V. All rights reserved.