Because the direct research object of philology is literature, and the main object of library and information work is literature, there is inevitably an overlapping relationship between philology, library science, information science and other disciplines, and sometimes it is difficult to draw a clear line.

Philology mainly includes the following research contents:

① Study the characteristics and functions of literature. Including the nature and definition of literature; The content, form, characteristics and value of the whole document, different types of documents and even individual documents in the process of development and circulation; The role and position of literature in the history of human development.

② Literature type research. Including the use of a variety of standards to divide literary groups and the relationship between various literary types. Some people call it document typology.

③ Research on the development history of literature and philology. Including the emergence and development of literature; The phenomenon of literature accumulation and loss in history and its inherent law: the arrangement and research, achievements and existing problems of people in different countries, regions and times; The development trend and prospect of literature.

④ Research on document circulation. Including the research on the development, change and distribution of documents, such as the law of increasing the number of documents and the relationship with the development of human knowledge; The relationship between literature half-life (aging law) and knowledge updating cycle; The relationship between the law of document distribution and the cross-infiltration of contemporary disciplines; The relationship between literature cross-citation and its frequency and the inheritance and utilization of information knowledge. The study of these laws constitutes the main content of bibliometrics. It is a relatively mature branch of philology, and its research is not only conducive to mastering the characteristics of literature, better collecting, managing and utilizing literature, but also has positive significance for understanding the academic development trends and trends, and even studying the growth law of the whole scientific knowledge.

⑤ Literature specializing in a certain subject. From this, specialist philology can be formed (see the catalogue of specialist philology).

⑥ Specialized research on a certain type of literature or a specific literary group. From this, some specialized disciplines can be formed, such as library science, patent philology, papyrus philology, Dunhuang philology and so on.

⑦ Research on some aspects of literature (such as edition and collation, etc.). ), and thus formed a version of science, collation and so on.