Urban green space (UGS), as a form of green infrastructure, has been given increasing attention in urban planning and its policies. The quality of a UGS is fundamental for the sustainable development of the urban economy, society, environment, and quality of human life, although UGS is unevenly distributed within cities. Aiming to analyze the quality of UGS at the scale of Jiedaos in China, this paper took Haizhu district in Guangzhou as a case study based on collected data from 2010 and aerial imagery from 2012. The Urban Neighborhood Green Index (UNGI) was established by combining four weighted parameters: the green index (P1), the density of buildings (P2), proximity to green areas (P3) and building height (P4). Results from comparing with green index show that (1) the UNGI performed better for UGS planning due to its ability of uncovering impact of the built environment and its accessibility on quality of UGS; (2) the UGS has significant effects on neighbors, which underlies social inequity of UGS supply and presents rich information for urban planning and decision making; (3) a small green field attaching to a community plays a key role in fulfilling the need of neighbors for green space, fitness, and leisure in China, which is usually ignored due to the ownership of private property. It suggests recognizing UGS and improving its quality in old towns as well as improving urban villages characterized by poor quality of green space with green infrastructures. The UNGI can inform city planners regarding their consideration of UGS, and it can contribute to measurements of sustainability and the development of green infrastructure.