This article is about the district in Tokushima Prefecture, Japan. There is another district with the same Japanese name (海部郡) in Aichi Prefecture, see Ama District, Aichi.
March 31, 2006: The towns of Kainan, Kaifu and Shishikui merged to form the new town of Kaiyō. On the same date, the towns of Hiwasa and Yuki merged to form the new town of Minami.