Introdução: As organisations responsible for providing accurate and up-to-date information, libraries are continuously experimenting with new technological resources and reshaping their services to meet the expectations of their users. At the beginning of the 21st century, social middays emerged as an additional opportunity for them to connect to these spaces and access their information resources. Objective: In addition, this study seeks to identify the characteristics of research into social microdays and libraries in stadunidense scientific production in order to monitor their evolution and point to trends. Methodology: In order to do so, Hjørland proposed descriptive research of a qualitative nature based on the domain analysis proposed by Mr Hjørland. The corpus consists of 69 articles, published in scientific journals of US Information Science. In this sense, it has been noted that social media and libraries have been discussed in the context observed since 2006, mainly in the context of university libraries. Results: A possible epistêmic community in training has also been identified. In turn, the Library 2.0 concept emerged as one of the theoretical contributions that influenced librarians and impacted services in the segment. In addition to Information Science, the knowledge produced on the interdomain analysed is spread across various fields, such as media, education, computer science, sociology, etc. Outside the term Web 2.0, social media is the most widely used by this discursive community, although social mid is highlighted as a trend. There is also a predisposition for research on practical applications, followed by theoretical studies. Conclusion: Emerging terms and representatives of the interdomain analysed have been identified not yet covered in the main thesauri used by field researchers.