The current ratio of dependence on food in Japan has remarkably grown and the significance of food self-sufficiency by concurrent agriculture may decline, while importantly conserving the natural environment, appropriate management of farmland. Okayama prefecture has an agricultural trend over more than 100 years of rice, barley and wheat cropping area with the rise and fall of its agricultural land use from the prior to the Industrial Revolution in Japan. Although rice reduction policy in Japan is scheduled to end in 2017, Japan is strongly subject to rice compared to other grains. In order to understand the role and scope of the agricultural sector in Okayama pref., it is necessary to review the changes in the related agricultural products for the long term. In Okayama pref., the cultivation and processing of some industrial crops including sericulture sector were thriving in the past, but, commercial agriculture was not well developed and the meaning of the production of cereals was greater than current production. Considering the part of agricultural characteristics by examining the cultivation of crops over the long term, planting area survey by variety confirmed that the greatest feature of rice cultivation in Okayama pref. is the diversity of varieties. In addition to various rice varieties, agriculture in Okayama pref. has a high sustainability, resistance and flexibility against changes on climate, policies and land use.