Objective  Based on the study of granite and dolomite mountain in Beijing, this study explored the differences of plant communities under different bedrock conditions, and provided scientific basis for vegetation restoration of granite and dolomite mountain in Beijing.

  Method  Three granite and dolomite mountains were selected in the experiment. Through the sample survey, the plant community characteristics of two different kinds of bedrock were analyzed from the aspects of species composition, biodiversity, altitude gradient characteristics, similarity coefficient, etc.

  Result  The results showed that: (1) there were 188 kinds of vegetation in granite mountain, belonging to 148 genera of 61 families; 95 kinds of vegetation in dolomite mountain, belonging to 80 genera of 38 families; all of them were dominated by Compistae, Fabaceae and Gramineae, which were the important resources of plant restoration and planting in two kinds of bedrock mountain. (2) By measuring different life styles, the dominant species of tree layer, shrub layer and herb layer between two kinds of bedrock mountain vegetation in Beijing can be used as important materials for mountain restoration. (3) Compared with the characteristics of plant community in granite mountain, it was found that there was no consistency between them; compared with the characteristics of plant community in dolomite mountain, it was found that there was a high consistency.

  Conclusion  The plant community species of different granite and dolomite mountain are consistent in dominant families and genera, which are important plant resources for ecological restoration of granite and dolomite mountain. By comparing the similarity between different mountains, we can not generalize the phytoremediation of granite mountain. We should pay attention to distinguish different site conditions. For the dolomite mountain, we can use similar methods and plant species to repair.