The production of the Satsuma Orange (Citrus unshu Hayata) in Oosima-gun is not so large as in other prefectures, though the orange is highly superior in quality and wins the great reputation. The orange industry of Oosima-gun is now one of the important enterprises in Yamaguti Prefecture. The Satsuma Orange of Oosima gun is larger in size, thinner in peel and sweeter in taste than that of other countries. The good quality of the orange in Oosima-gun seems to be due to the suitable climatic condition, the skillfull management of the orchard and the exact selection of the excellent varieties or strains. The Oosima gun is, consequently, one of the most suitable and profitable districts for the orange culture.