A study on indigenous diatoms was carried out at 10 sites from May 2014 to December 2016 in marine and freshwater in Korea. Seventeen species of diatoms are new to Korea and they are divided into 3 classes, 4 subclasses, 10 orders, 14 families, and 16 genera. The nomenclatures, references, dimensions, specimens examined, local habitat, distribution in Korea, and photograph are reported here. Seventeen species found in marine, freshwater, and brackish water showed species-specific habitats.

• Joon Sang Park(Marine Ecosystem and Biological Research Center, Korea Institute of Ocean Science & Technology)
• Suk Min Yun(Protist Resources Research Division, Nakdonggang National Institute of Biological Resources)
• Sang Deuk Lee(Protist Resources Research Division, Nakdonggang National Institute of Biological Resources)
• Joon Baek Lee(Department of Earth and Marine Sciences, Jeju National University)
• Jin Hwan Lee(Department of Life Science, Sangmyung University) Corresponding author