The rapid advancement of urbanization has led to serious damage to the ecological environment and a sharp decline in biodiversity. Although the areas of community parks are small, they have the largest number and great potential for protecting biodiversity. Spontaneous plants are not only an important part of plant diversity in the park, but also provide essential food sources and habitats for animals, therefore, their ecological values cannot be ignored. This paper focused on the community parks in Xicheng District of Beijing, based on the comparative analysis of niche width, overlap index and plant diversity of spontaneous herbs, the community types of spontaneous herbs were explored to further clarify the community characteristics of spontaneous herbs in small-scale urban green space under the mode of intensive maintenance and management. The results were as follows. (1) A total of 38 species of spontaneous herbs were recorded, belonging to 22 families and 36 genera. (2) Capsella bursa-pastoris, Chenopodium album, Solanum nigrum, Taraxacum mongolicum etc. had wide niche width; the niche overlap index (O_ik) between the dominant species of spontaneous herbs ranged from 0 to 0.62. (3) In terms of plant diversity characteristics, the Patrick index and Shannon Wiener index of Yuetan Park were the highest, and the Pielou index of the Park in Nanlishi Road was the highest. (4) Using TWINSPAN classification method, the spontaneous herb communities were divided into 9 community types. V Chenopodium album + Capsella