Abstract: Zoysia macrostachya is a kind of salt-living plant. It mainly grows on salt soil along sea bank. Most species in its section system are salt living. Its communities belong to original beach community. Zoysia sinca and Zoysia macrostachya are suitable lawn grasses for cities along seas. Zoysia sinica is a kind of lawn grass with salt tolerance character. Its communities mainly distribute at 2~40 meters height along seas. Its ecological breadth is wide. The pH values of soil where it grows are between 7.2~7.9. Zoysia sinica communities are single dominant and its cover degrees are between 60~90 percent. There is abundance variation in Zoysia sinica. 17 samples are divided into 6 types by Fuzzy method and the differentiation among the types are great. PCA analysis shows that sexing reproduce organ such as the height of spike, and nourishment organs such as the length of leaf and the increasing speed of stolen are important indexes for studying the variations under the genus of Zoysia sinica.

Key words: Zoysia macrostachya, Zoysia sinica, community, fuzzy clustering