In applied linguistics, studies on rhetorical moves using genre analysis approach have been prevailingly done. This type of research uses documents of research articles (RAs) for analysis. This research tries to explore the rhetorical moves in introduction sections of academic journal articles with two different discourse communities: Technology and Economics. It also attempts to provide the writers, especially the novice writers with general knowledge of rhetorical moves of two different discourse communities: 10 of technology RAs and the other 10 of economics RAs. These documents are taken by purposive sampling based on certain criteria. Thus, it a qualitative research using documents as the data for analysis that is also considered content analysis. The analysis is based on the genre analysis approach with CARS as the instrument. All inferences are derived from the results based on the CARs. The result shows that there are some differences of CARS adopted by the authors of the two discourse communities. Therefore, it is vital for the writers to pay attention to the rhetorical moves of introductions of these two different discourse communities. The researcher recommends that the prospective writers adopt these CARs for better adaptation to these two discourse communities when expecting to write the same RAs in these two publications.