Urban parks play an important role in the formation of spatial structure and form in urban spatial development, as an important component of green spaces. In recent years, research on the confluence of green spaces and fringe belts, although rare, has demonstrated the value that research on the relationship between the two can provide references for landscape management and planning. Taking Nanjing as a typical case, this study investigated the spatiotemporal evolution of urban parks and fringe belts since 1901 in terms of urban morphology. This study mapped the distribution of urban parks in several time points by the methods of historical materials climbing, field surveying, and historical maps vectorizing. By exploring the evolutionary process of parks' planning, construction, and adaption, the land use in the inner, middle and Ming fringe belts was also explored. The results show that the parks' distribution in different fringe belt varies over time. The Ming fringe belt has become continuously, while the inner and middle ones are the opposite. The amount and area of parks in the Ming fringe belt increased gradually, but the middle one decreased dramatically. This research provides a novel insight based on urban parks into understanding the formation of urban spatial structure.