In hilly and mountainous areas, the operation and maintenance of farm and forest and is becoming a major problem Makeupas the number of inhabitants decreases and the impact of the international agricultural situation is felt. Based on an investigation into actual conditions which targets the individual farmers, this problem must be studied with a view to a comprehensive policy for hilly and mountainous areas. From this standpoint, the present research has elucidated the causes for the occurrence of unplanted paddy fields and abandoned cultivation land in terms of a structural analysis of farms in the case of the Sugo settlement, Hachiman-cho of Gifu Prefecture, and has studied trends in the maintenance of hilly and mountainous areas based on this.1. The conditions of unplanted paddy fields and abandoned cultivation land were analyzed with regard to the town as a whole and the targeted rural settlements. Rural settlements with many unplanted paddy fields are found along the major rivers and in the valley plains of mountainous areas. The unplanted paddy fields are fields which are far removed from the farmers and fields which are irregularly shaped or which have a poor work environment on tableland. The average aomunt of farmland owned by farms with unplanted paddy fields is 60 ares, and the unplanted paddy fields account for approximately 20% of this. In addition, these farms possess approximately 40 ares of abandoned cultivation land. The average amount of farmland owned by farms without unplanted paddy fields is approximately 30 ares. With regard to farms with unplanted paddy fields, the number of family members, the age of the householder, and the age of the successor of the farmer are greater than in the case of farms without unplanted paddy fields.2. An analysis was made of the state of the living environment which is one of the conditions of stable settlement in the rural settlement in question. The state of the living environment was considered in terms of living spheres such as the location of the main public facilities, commuting, and shopping. There are no main public facilities in the rural settlement in question ; these are all concentrated in the key settlement of the old village, and the town center. There is a high degree of dependency on the town center for the living sphere, and it was clear that the living sphere of farms with unplanted paddy fields is narrower than farms without such fields. 3. An analysis was made of family makeup and the changes therein, and their relation to the state of managing farmland. With regard to farms with many uncultivated paddy fields, the holding farmland area is comparatively large, and the householder is primarly engaged in part-time labor. The “decrease” in the number of family members combined with the “ageing” of the average age of the family can be observed in farms with a large holding land aera. It would seem that these changes in family makeup are related to the incidence of unplanted paddy fields.4. The relation between changes in family makeup and the state of managing farmland was modeled according to the 3 cases of (a) unstable maintenance of farmland, (b) low-stable maintenance of farmland, and (c) no unplanted paddy fields. While referring to survey results on trends in hilly and mountainous areas, the trends in hilly and mountainous ares maintenance were studied based on these 3 models. As a result, it would seem necessary to secure oppotunities for income generation in industries other than agriculture and forestry, to promote the development of living environment infrastructure, and to adopt not only ageing countermeasures but also a support system for infants and toddlers. Furthermore, it would appear necessary to establish a low-stable maintenance system for farm and forest land.