How do parents support their preschooler's bilingual heritage language development at home? It is a kind of challenge Chinese-Australian parents face during their everyday home practice. Whilst empirical studies have investigated the effects of weekend heritage language schools on children's heritage language learning (Curdt-Christiansen, 2006; Li, 2005; Liao & Larke, 2008), little is known about the ways in which adult interactions and communication contribute to children's heritage language development through everyday life practices. The exploration in the research site of a shared book reading, is used to investigate this question. In this study, Vygotsky's (1987) cultural-historical concepts of social interaction and mediation form the foundation of this research project. This paper particularly focuses on how parent-child interaction effectively supports children's bilingual heritage language development in a shared book reading practice. Hedegaard's (2008) dialectical-interactive approach is used to frame the analysis of shared book reading practices. The paper analyses an episode where Lin (4.5 year old girl) and her father reading an English story in Chinese to identify how parents and the child engage in shared book reading and how parents support their children's storytelling and heritage language practice. This paper unpacks the various dimensions of parent-child shared book readings and ends with a discussion of the effectiveness of parents reading with children, in order to determine the pedagogical strategies parents should use in terms of cultural-historical theory and the data. It is argued that parents' shared book reading with their children can be an effective pedagogical strategy to support children's language development. The findings regarding family pedagogical strategies can also be extended to apply to communication and engagement between teachers and children in general school settings.