Abstract: Existing reviews on positioning theory have predominantly focused on delineating its developmental trajectories, with limited attention to its theoretical underpinnings and data sources. A deeper exploration of these aspects, however, can illuminate the pathways for the theoretical innovation. Through a systematic review of relevant literature, this study identifies three key shifts: 1) The analytical focus has evolved from narrative analysis and dialogic analysis, through interactional analysis, to a more integrated approach. 2) The theoretical foundations have been informed by speech act theory and narratology, Bakhtin’s dialogic theory and Goffman's production format, conversation analysis and interactional sociolinguistics, as well as the theory of indexicality and relation maxim within Grice’s Cooperative Principle. 3) There has been a transition from fabricated and interview narratives, through small stories, to conversational narratives and ethnographic fieldwork. Positioning theory has introduced novel perspectives to sociolinguistics, foreign language teaching, and pragmatics. In summary, the evolution of positioning theory is largely attributable to a steadfast respect for linguistic facts and the incorporation of innovative theoretical perspectives.