Abstract: Casuarina equisetifolia is one of the main protective species in Nanji Island, this study aims to prove the planning for the construction of the shelter forest in Nanji Island and understand the impact of different environmental factors on the Casuarina equisetifolia community. Methods: 24 community quadrats were established. Multivariate regression trees(MRT) and self-organizing feature mapping(SOM) were used in this study to classify the surviving communities of Casuarina equisetifolia. Results show that: (1) The 24 selected quadrats could be divided into 4 community groups associations and the results obtained using various research methodologies were highly consistent. (2) The relationship between the survival condition of Casuarina equisetifolia and water content and the organic matter in the soil indicates that being one of the windbreak plants, Casuarina equisetifolia plays an important role in the conservation of soil and water, wind prevention and sand fixation, as well as the improvement of the soil structure. (3) The combination of SOM and MRT can be used as a comprehensive analytical method in future researches on the relationship between plant species and environmental factors.