Since the mid-twentieth century, nature centers have offered environmental education programs for surrounding communities. They play a significant role in nonformal and informal environmental education, with audiences from children to seniors. They also generate social impacts on communities. This research used qualitative and quantitative methods to investigate nature centers' social impacts from the perspectives of nature center leaders and staff. Findings showed that leaders and staff recognized three categories of social impacts: impacts on “human,” impacts on “human-society,” and impacts on “human-nature.” The social impact on human includes health, human development, and personal achievement. The social impact on human-society includes sense of community and facilitating community building and solidarity among people of different races, ethnicities, and social-economic backgrounds. The social impacts on human-nature includes connectedness to nature, sense of place, and catalyzing environment stewardship. Among these three categories, nature center leaders and staff prioritized human-nature over human and human-society. This study begins to fill the gap in nature centers' social impact analysis.