Abstract:The processes of forest succession could be expressed by the dynamic characteristics of dominant populations in forest. The dynamic characteristics of two heliophyte species, Castanopsis chinensis and Schima superba in forest succession in Dinghushan were studied. The main results were as follows: 1. The niche breadths of the 2 species increased after their intruding in the needle-leaved forest, and reached the maximum when they became the dominant populations in evergreen broad-leaved forest, and then reduced gradually, but did not disappear at the climax stage. 2. In the process of the succession, changes in distribution patterns of the two populations were from clustering to random. 3. During the succession, the association and niche overlap of these two populations with Pinus massoniana population decreased, while with some mesophyte populations increased at first and reached at the highest in the evergreen broad-leaved forest stage, then reduced at the late stage. The results suggested that the features of the two populations were that of pioneer species; and the cycle and regeneration of mature community could cause the uneven and inlaying in community structure which is the reason for existence of these heliophyte population at the late stage of succession.