The everyday conversations that occur between mothers and children, particularly those involving reasoning, are a major vehicle for the transmission of information and values to young children. This study explored the manner in which five Australian Chinese mothers engaged in reasoning talk with their preschool-aged children. A total of 83 instances of spontaneous reasoning talk were identified and analysed according to the manner in which the mothers justified their claims or statements, using Hasan's reasoning structure framework to underpin the analysis. Both regulatory and nonregulatory contexts were analysed. The analysis revealed that in regulatory contexts, where a child's behaviour is being controlled (for example, "eat up your dinner quickly"), mothers provided more socially based reasons to justify their directives. In nonregulatory contexts, such as shared reading, they used more logical reasoning based on universal laws of nature. The findings suggest that the reasoning talk that takes place between mothers and children provides a rich opportunity for mothers to convey their values to their children, with implications for children's learning across a number of domains.