Closeness and distance, intimacy and setting boundaries, harmony and conflict were inevitable in intimate social relations such as those in families. A considerable proportion of parents and adult children experience these mixed feelings. Researchers agreed that the feelings of ambivalence. However, the current knowledge about intergenerational ambivalence primarily came from the findings of Western studies, and there was lake of studies on whether the Western-derived concept of ambivalence could be applied to the traditional families like those in rural China. Furthermore, with profound social and economic transformations, China was facing to the urbanization and migration of population, resulting in the more and more dispersion of young grandchildren and older parent left behind in rural areas as a result of massive rural-urban migration. Grandparents became crucial caring resources in the rural families. This study investigated the effects of grandchild-caring provided by older parent on intergenerational ambivalence in rural China, where was a traditional society undergoing dramatic demographic, economic, and social changes. In former studies, many researchers had studied the effect of the grandchild-caring on the elders’ well-being, generally based on the role strain or role advantage. However, the conclusions still were confused. Different from the grandparenting in West, as a role of grandparenting, the grandparents were entitled to provide caring for their grandchildren, especially for the grandchildren of their sons. Although the grandparenting role might create a sense of fulfillment, as to the lack of other social resource, it was often long-term demanding, and may leave older parents with few options of exit, companying with a sense of ambivalence. Thus we employed the theory of role strain to explain the effects of grandchild-caring on intergenerational ambivalence of older parents in rural China. Using the data from the survey “Well-being of Elderly in Anhui Province, China” conducted in Chaohu area by the Institute for Population and Development Studies at XXX University, in conjunction with the University of Southern California and Syracuse University, we carried out the two-level Tobit models to examine the effects of grandchild-caring on ambivalent feelings reported by the older parents toward their adult children. We found that, because of less access to the formal social supports in rural China, grandchild-caring provided by older parents to their adult children was associated with higher levels of ambivalent feeling toward their adult children, which supported the theoretical explanation of the role strain theory for grandparenting. Due to the gender role and gender division of household work in Chines families, the grandchild-caring, especially the low intensity of caring, heightened the strains of the older fathers and thus worsen their ambivalent feeling, but not for the older mothers’. Furthermore, due to the strong son preference in rural China, the older parents reported greater ambivalence toward sons than toward daughters. Especially for the older parents providing the low intensity care for their adult daughters experienced the lower level of intergenerational ambivalence. These results suggested that the strong interdependence between older parents and their children, especially the preference for the sons, would create the greater feeling of ambivalence.