Eight examination stations were constructed in young red pine forests and mature evergreen broad-leaved woods. A total of 32 quadrats of 10 × 10 m each were examined for vegetation and mushroom distribution and diversity once a week for one year. A total of 9707 individual mushrooms, amounting to 1470.23 g in dry weight, were analyzed for fungal communities. The results were arranged in a sequence of succession. The mushroom diversities, expressed as Shannon's H-, increased constantly to the equilibrium at around 3.0 in the climax forests. The distribution of the proportion of saprophytic fungi depicted a similar curve and reached equilibrium at around 0.3. The seasonal segregation in mushroom fruiting also developed and reached equilibrium. Ecological distances between the forests were estimated from the mushroom results and were compared with those estimated from the woody plant diversities. Fungal succession took place more rapidly or was more exaggerated than that of woody plants. From these results, the fungal succession and diversity in the climax forest was discussed. © 1994, Mycological Society of Japan. All rights reserved.