Mutuality of support provision is a necessary precondition of family solidarity. However, the exchange of care between grandparents and grandchildren has largely been neglected. Using data from the fourth wave of the Anhui Study in China, this study investigated determinants of support exchange between grandparents and grandchildren. Results showed that more grandparents received support from than provided support to their grandchildren. A higher percentage of older adults exchanged support with the grandchildren of their eldest child if that child was male rather than female. Older adults who had strong emotional bonds with the middle generation, especially with sons, or had experience caring for grandchildren were much more likely to receive support from and provide support to their grandchildren. This study confirms the intergenerational solidarity theory and norms of kinship obligation in rural China, where social services are limited.