Plant diversity is one of the most important natural heritages of a region, and is an indispensable condition for existence and development of humankind. Recognizing and understanding this natural heritage as well as conserving it is our responsibility which should not be evaded. Beijing is a worldknown cultural capital and its numerous cultural historical monuments have been recorded and evaluated, yet its distinctive natural heritages have not yet been paid attention to. This paper focuses on the levels of plant species and communities of Beijing region, dealing with their composition and characteristics, indicating that transitional climate and complex geological and geomorphological conditions (that is its geodiversity) are the foundations of its plant diversity. Lastly, threats the Beijing plant diversity is confronted with at present time and their alleviating methods are indicated.