Abstract: The habitat quality and connectivity structure of urban small and medium-sized green space play an important role in promoting urban biodiversity. Under the influence of community life circle services, the urban green space construction in China has formed a typical and repetitive green space pattern. Exploring the minimum quadrat of green space composition and its habitat elements and morphological structure is an important way to improve the urban ecological quality and green space planning and design. This research, based on the basic achievements of urban site habitat construction and ground cover plant community design in northwest China, takes the green space in the old and new urban areas of Xi’an City as the objects. It puts forward the basic scale quadrat of “2 km×2 km” urban block green space habitat network by using the research paths of review, geographic information interpretation-field surveys and cluster analysis. It has found four typical patterns, which are single-core radiation, multi-core dispersion, corridor crossing and scattered distribution. It also analyzes the coupling relationship between the form, elements and spatial pattern of the quadrat, and explores the ways to improve the construction of green spatial habitat network in the quadrat system.