ABSTRACT There is growing public concern in China about the large number of children whose parents have left them behind because of massive rural-to-urban labor migration over the past few decades. It is estimated that there were 61 million left-behind children in China in 2018. Because of the prevalence of instant communication applications, such as WeChat, left-behind children in China can maintain family relationships with their migrant parents through social media. This study examines how left-behind children use WeChat to sustain long-distance family relationships. Conducted during the COVID-19 pandemic, the research involved online interviews with ten children and ten online workshops with thirty-one child participants. The data collected from the workshops and interviews suggest that a gap still exists between children’s communication needs and the technological affordances of social media. Mediated communications via WeChat are not always child-friendly and can have implications for the success or failure of parent-child communication in Chinese separated families. Despite these challenges, children demonstrate creativity in navigating the uncertainties of long-distance communication and relationships. However, this process is strewn with difficulties that the adult family members in the participant families have overlooked.