This dissertation explores why and how firms partner with grassroots nonprofits—politically disadvantaged charitable foundations, social services organizations, and advocacy groups that are prone to government surveillance, predation, and repression. In the first chapter, I demonstrate that low political status of nonprofits helps turn corporate philanthropic initiatives into core business activities for the interest of corporate donors, in particular market risk mitigation, business networking, and product marketing. In the second chapter, I show that structural characteristics of locality-specific performance ratings—namely, evaluation frequency and ambiguity—condition capacity building and issue versatility of politically disadvantaged nonprofits, which have implications for their attractiveness in the eyes of potential corporate donors. In the third chapter, I document that breadth of corporate support that a nonprofit can possibly garner—which reflects resource mobilization base for social impact—varies according to the organization’s political status. Through an empirical investigation of grassroots nonprofits in contemporary China, on the basis of a mixed-methods design, this dissertation advances a nonprofit-centered political perspective on corporate social responsibility and points to the significance of political contestation and commerciality in firm-society collaborations.