Parks have evolved into essential urban sanctuaries, especially amid the COVID-19 pandemic. While previous studies have investigated the impact of lockdown measures on park visitation, limited attention has been given to the impacts of sudden easing of containment measures, especially the “unfencing” of parks in densely populated cities. Employing a regression discontinuity design (RDD), this study analyzes changes in park visitation behaviors among Shanghai residents (N=563) following the policy relaxation. We focus on three key aspects: visitation behavior, choice of park types, and activities undertaken within public parks compared to gated community greenspaces. The results reveal a short-term decrease in visits to nearby parks, reduced public transit use, and shorter travel times. This trend was accompanied by a reduction in visitation to various park types, especially larger ones, with waterfront greenspaces being an exception. However, visit frequency and duration remained unchanged. A significant decrease in exercise and enjoying weather was observed in both parks and community greenspaces. Additionally, there was a noticeable reduction in activities like playing with children, nature appreciation, specifically within community greenspaces. These findings extend our understanding of urban residents' engagement with greenspaces in a transitioning post-pandemic context, providing valuable insights in managing greenspaces during and after public health crises.