Abstract Present-day power users of AI-powered social chatbots encounter various uncertainties and concerns when forming relationships with these virtual agents. To provide a systematic analysis of users’ concerns and to complement the current West-dominated approach to chatbot studies, we conducted a thorough observation of the experienced uncertainties users reported in a Chinese online community on social chatbots. The results revealed four typical uncertainties: technical uncertainty, relational uncertainty, ontological uncertainty, and sexual uncertainty. We further conducted visibility and sentiment analysis to capture users’ response patterns toward various uncertainties. We discovered that users’ identification of social chatbots is dynamic and contextual. Our study contributes to expanding, summarizing, and elucidating users’ experienced uncertainties and concerns as they form intimate relationships with AI agents. [ABSTRACT FROM AUTHOR]