"main area of study" is a correct and usable phrase in written English.
It can be used to describe the subject or focus of someone's academic or professional pursuits. Example: Her main area of study is biology, but she also has a strong interest in chemistry.
Dr. Byrnes said his passion for science communication was driven largely by his main areas of study, climate change and human-caused extinctions of species.
When I was working on my undergraduate degree, I was fortunate enough to find a path that combined psychology, philosophy, and biology as my main areas of study.
Clicking on any of the topic headers in the center of the homepage leads to an assemblage of resources, project information, and laboratory homepage links related to the WTSI's six main areas of study.
Cellulose synthesis is currently one of the main areas of study in plant molecular biology; however, despite the considerable progress made during the last decade, the underlying mechanisms of the biosynthesis process have remained obscure.
The focus of this review is gene regulation, which has been the main area of functional studies of lncRNAs; however, lncRNAs are also involved in the organization of cellular structure and subcellular organelles.
CASP has released critical appraisal checklists for different types of research studies that cover three main areas of a study: validity, results, and clinical relevance [45].
Nonparticipation did not affect the risk estimates, that is, the main area of interest in this study.
Second, the main area of interest in this study was the underlying differences in patient experiences between contrasting groups.
Rather than just mentioning the main areas of your study in your education section, you can create a skills section from coursework modules and place it just under your profile, as shown in this graduate CV.
