The seed and seedling stages of 19 species and 2 varieties of Fagaceae in Japan were studied comparatively. These species were clasified into two groups on the basis of the difference of germination rate. One is the group of species whose seeeds germinate rapidly after their falling, and then elongate their roots long enough within the mast year. Another is the group of species whose seeds do not germinate until the next spring of the mast year. The species of Lepidobalanus show the large diversity of seedfalling time and germination rate. This diversity corresponds to their distributional diversity, that is, the species of Lepidobalanus distribute widely in cool temperate and warm temperate zone. Contrary to this diversity of Lepidobalanus, the species of Cyclobalanopsis show similarity of seed-falling time and germination rate. Corresponding to this similarity, the species of Cyclobalanopsis distribute only within warm temperate zone. The distribution and behavior of some important species such as Fagus crenata, Castanopsis cuspidata, C. cuspidata var. sieboldii, Quercus variabilis, Q. acutissima, etc. were discussed precisely using field and experimental results on the seed and seedling stages.