Academic conferences have become an important rite of passage for academics to develop their professionalism and obtain promotion. Nowadays, conferences are a venue not only for exploiting, exchanging or sharing knowledge, but also for building connections, carrying out academic/commercial promotion, and even selling products or services. Conferences are without a doubt important activities in researchers' lives, and a significant element in the development of their research profiles. Thus, full understanding of conference language and its component genres can help scholars become well-situated members of their discourse communities. Yet, compared to the extensive research on written academic discourse, studies on spoken academic discourse are underrepresented, and conference presentations (CPs) are one of the less explored but truly essential genres for academic researchers. Thus, to meet this research need, the present study attempts to examine how non-native English speakers present and interact in a CP, specifically concentrating on Mandarin Chinese speakers, the largest linguistic group learning English nowadays. A total of 44 presentations on ESP issues delivered at an international conference were observed, focusing on how the speakers interacted with the audience and how they presented their stance in their CPs. The results indicate that, first, the speakers intentionally deployed certain lexical devices to ensure that their presentations were delivered coherently, and relied on both verbal and physical devices to direct the audience's attention to the projected semiotic images. Second, the ambience of interacting with the audience changed from a rigid formality to lively variety as the CP progressed. Third, the feature of shifting from an impersonal voice to a more personal tone in their CPs was deliberately adopted by the speakers to build up interpersonal connections and a personal reputation in the research community. Pedagogical implications for teaching ESP and suggestions for future studies are also provided.