We examined the food habits of the Asiatic black bear in relation to availability of main foods (seeds of Fagus crenata, Quercus crispula, and Q. serrata) from 1213 scats in Shirakawa Village, Gifu Prefecture, Japan, over seven years. The study area comprises natural forest (approximately 88%) and had little bear-human conflict. The food composition was different in all months over the years. The bears mainly fed on green vegetation in spring, until the end of July, and on hard mast in autumn when its production was abundant. Insects, such as the Formicidae family, made up a higher proportion of the diet from July to August. In autumn of low hard-mast production, the bears consumed various fleshy fruits. The annual variation in food composition was especially greater in September because of the fluctuation in fruit production rather than a phenological time lag.