After the development of the experimental
HEMU-430X, Hyundai Rotem and Korail signed multiple agreements from June to December 2016 to supply high speed
electric multiple units, the first of its kind in South Korea in revenue service (the HEMU-430X is also an electric multiple unit, but it is not for revenue service and mass production). The agreements involve ordering of two variants: 2 eight-car EMU-320 units (with an operating speed of 320 km/h) and 19 six-car EMU-260 units, to be delivered around 2020 to 2021. In September 2016, Korail held a contest for the public to decide the design of the new models. In 2017, a mockup of the chosen design was exhibited to the public to promote the sister train (EMU-260) and receive feedback. On March 28, 2022, it was reported that the EMU-320 consisting of 25 units for Korail and 19 units for
SR Corporation were scheduled to be delivered from December 2023 (the revised numbers as in later reports shown below are 17 units (19 units if the initial orders are included) and 14 units, respectively). However, this was delayed mainly because some elements of the EMU-320 had to be re-designed due to serious concerns about excessive noise levels in the cab and passenger compartments. To reduce noise levels, measures including improving the pantograph's shape and adding sound insulation to the ceiling and floor have been taken. Hyundai Rotem had to pay 19 billion won in damages for the delay in delivery. The two pre-series sets built by Hyundai Rotem following a 2016 contract were delivered to Korail in November 2023 and were expected to begin operations in 2024. The model was officially named "KTX-Cheongryong" () in April 2024, where the word 'Cheongryong' () in
Korean means '
blue dragon'. This name was selected by members of the public, which signifies "a blue dragon soaring vigorously to bring hope to the people" and matches the Year of the Blue
Dragon (i.e. 2024) according to the
Korean zodiac. The remaining 17 trainsets ordered by Korail are scheduled to be delivered between April 2027 and March 2028, and another 14 trainsets to be delivered to SR Corporation from 2027 onwards. In September 2024, the EMU-320 high-speed train (the original name is used for further research and sales after naming as KTX-Cheongryong in South Korea) obtained the design certification of
Technical Specification for Interoperability (TSI), which paved the way for Hyundai Rotem into the European high-speed rail market. On June 19, 2025, it was reported that Hyundai Rotem introduced upgrades to KTX-Eum with significant improvements in noise, vibration, and ride quality. These upgraded trains have been supplied to Korail from 2025 onwards, and similar improvements will also be introduced to the next batch of KTX-Cheongryong trains which are expected to be supplied to Korail and SR Corporation from 2027 onwards. The upgraded trains feature buffer devices with improved bogie performance, which will increase the strength of the lower part of the car body that would lead to reduced external impact felt by passengers. Noise inside the train cabin will also decrease with improved sound-absorbing material area, as well as sound-absorbing plywood with enhanced sound-absorbing properties on the floor of car body with minimized friction noise from the railway. ==Design==