In this study, a long-term transition on arable land use and planted acreage in Okayama prefecture is mainly examined. There were no substantial changes at the area of the cultivated acreage and the use level of arable land before World War II. In statistics after 1965, the use level of the cultivated acreage and arable land has decreased remarkably. In this point, it is clearly observed that the cultivated acreage in 2005 has decreased by 60 percent compared with 1960 and the area of the field has importantly decresed in the same period about 80 percent. In addition, the uncultivated arable land in 2005 has increased double (or more) compared with 1975. Finally, this analysis concretely illustrated decreasing of man's concern for the production of food. Because a part of the safety of food is threatened recently, it is important in above all to procure food safely. Moreover, to reinforce a domestic production of food the decision and the execution of an effective policy are requested.