<p>Despite trends toward gender equality in mainland China, traditional gender ideology prioritising sons over daughters may continue to shape intergenerational support, including older parents’ provision of grandchild care. Such son favouritism is also suspected to modulate older parents’ expectations of future reciprocity. Thus, this research investigated how older parents’ provision of grandchild care differed between sons and daughters within the same family, and whether their associated expectations of reciprocal support also diverged for sons and daughters. Utilising data from the 2018 wave of the China Longitudinal Aging Social Survey, this study identified son favouritism by evidence of consistent and robust son preference in grandchild care provision and expectations of financial and instrumental support. Then, a path analysis indicated that providing grandchild care for sons was positively associated with expecting support from them, but negatively with expecting support from daughters. Similarly, providing grandchild care for daughters was linked to expecting more support from daughters and less from sons, although these associations were significantly weaker. These findings revealed that older people’s allocation of care resources and prospects of later life followed a pattern of son favouritism in mainland China. The results contest the argument of gradual increases in gender equality inside Chinese families. Instead, the study suggests that the male-centred values fundamental to traditional gender ideology prevail and reproduce themselves in contemporary China.</p>