Urban residential green spaces constitute a vital element of the urban green space system. Spontaneous plants, as a distinctive form of vegetation within residential green spaces, exhibit robust tolerance and high plasticity. They possess considerable ecological, economic, and aesthetic value, which should not be overlooked. This study focuses on the spontaneous plants within 78 residential communities situated in the urban area of Xi’an City, Shaanxi Province. Through field investigations and statistical analysis, the characteristics of species diversity in spontaneous plants within green spaces of residential communities in Xi’an City were examined. The distribution patterns of diversity and their influencing factors for spontaneous plants across various urbanization gradients, habitat types, and residential community characteristics were analyzed.The research results will help supplement and improve the study of urban vegetation in Xi’an and have essential scientific significance for further exploring the mutual feedback mechanism between urbanization and urban vegetation. It also has important scientific value for the in-depth protection and management of urban biodiversity and urban rewilding.