The wild grass communities extensively distributed in North China is a secondary coenotype into which the primeval vegetation was turned by artificial destroy. Now, papers studying wild grass communities by the quantitative method are rare. This paper made a cluster analysis of the wild grass communities on Mount Tai by a group-average method. At the level d=2100, we can distingush 12 coenotypes. The results also show that;
1. It is practical to completely classify the wild grass communities by the numerical method.
2. The major coenotypes are coincident with the traditional classification, in which there are eight communities defined as association types.