According to survey data of ancient and famous trees of Beijing in 2007, there are 39 408 ancient trees, which belong to 66 species (including varieties, forms and cultivars) from 47 genera and 28 families in Beijing. Analytical studies are conducted on quantity, composition, geographical elements and rare, endangered, key protected, distinctive species. The results show that ancient trees of Beijing have the following characteristics: species are abundant, quantity is large; geographical elements are complex, character of temperate zone is obvious; rare and distinctive species account for a considerable proportion.