There are five cultivated species in Avena L. They are Common oat (A. sativa L.), Abyssinian oat (A. abyssinica Hochst.), Red oat (A. byzantina Koch.), Small oat (A. strigosa Schreb.) and Naked oat (A. nuda L.). Naked oat is characterized by its hulless seeds, while other oats by their hulled seeds. Naked oat is mainly planted in China and hulled oats are grown in other countries. Therefore, Naked oat has an important place among oats in the world. However, the viewpoints on the origin and taxonomy of Naked oat were disputable among some researchers. The authors believe that the origin locality of Naked oat would be the adjacent region of Shanxi and Inner Mongolia, and the taxonomic status of Naked oat would be an independent species, i.e. A. nuda L.