ken (prefecture), central Honshu, Japan. It lies along the Sea of Japan and occupies an area of 1,642 square miles (4,252 square km). The coastal plain is indented by Toyama Bay. Watered by numerous rivers, including the Shō, Jinzū, and Kurobe, the prefecture is an important rice-producing area. The mountainous interior rises to 9,892 feet (3,015 m) in Mount Tate, which lies in Chūbu-sangaku National Park. The mountains are a source of hydroelectric power and minerals that serve as a basis for the chemical, textile, machinery, pulp and paper, and steel industries.

Toyama, the prefectural capital, is an old castle town located at the mouth of the Jinzū River. Since the 17th century it has been the chief centre for the production of patent medicines and drugs. In 1964 Toyama was joined with Takaoka to form the Toyama–Takaoka New Industrial City. The city is also an important educational, chemical, and textile centre. Other important towns on the coast include Shimminato, Namerikawa, Uozu, and Kurobe. Pop. (1985) city, 314,111; prefecture, 1,118,364.