Historically, Japan was divided into a number of provinces called koku, which were in turn classified according to both their power and their distances from the administrative center in Kansai.

Therefore, an alternative explanation is that Chūgoku referred to provinces between Kansai and Kyūshū, which was historically important as the link between Japan and mainland Asia.

However, because some of the easternmost provinces were later subsumed into prefectures based primarily in Kansai, those areas are, strictly speaking, not part of the Chūgoku region in modern usage.

The city of Hiroshima, the "capital" of the Chūgoku region, was rebuilt after being destroyed by an atomic bomb in 1945, and is now an industrial metropolis of more than one million people.

Overfishing and pollution reduced the productivity of the Inland Sea fishing grounds; and San'yo is an area concentrated on heavy industry.

The Chūgoku region is characterized by irregular rolling hills and limited plain areas and is divided into two distinct parts by mountains running east and west through its center.