This study reviews the current trends of research in English for Academic Purposes (EAP) as a subfield of Applied Linguistics. Through an extensive review of literature and an undertaking process of data collection, 15 books, 6 book chapters, and 347 research articles (RAs) were analyzed for identifying the major issues in EAP. Drawing upon the grounded approach, it was found that Academic Writing, Curriculum Development, and Critical EAP were the most challenging issues in EAP studies. Each of the research themes subsumed important issues such as genre analysis and approaches to teaching academic writing for Academic Writing; discussions on standard variety of English in academic contexts and practice of EAP among local students and teachers for Curriculum Development; and, critical thinking and pragmatism for Critical EAP. These issues and challenges explained in this paper hoped to be helpful for EAP to be matured as a field, and see itself in charge of preparing students to hold new roles both in academic and cultural contexts. However, it is acknowledged that, the concerns and issues are still unresolved and further research is needed for responding to them.