Researchers found that (1) the species richness, species evenness, Shannon-Wiener index and species dominant index all increased with the succession, indicating an obvious species adding process in the community development; (2) the species substitutions were significant in early succession (early stage to 30 years), but the importance values of major functional groups (nitrogen fixing species, dry-tolerant species and leanness-resistant species) showed no evidence of decrease from year 4 to year 60 and over, suggesting that physical conditions (water, nutrition) have strongly controlled the species assemblage through the functional group compositions on the sites; (3) the within-group community similarities decreased from over 0.515 in year 4 to 0.251 in year 60 and over, illustrating a tendency of stochastic direction of vegetation succession in the later stage. We concluded that the organismic model does not satisfactorily explain the succession process.