Abstract:  Starting from the 21st century, Earth science has entered into the era of Earth system science, which in turn has gradually become an important guide for Earth science, exerting great influence on all branches of Earth sciences. In the present paper, the research content and task of historical geology are discussed in both traditional Earth science and Earth system science. The research on historical geology is divided into the following five stages: the enlightenment stage (before the end of the 18th century), the restricted historical geology (stratigraphy) stage (from the late 18th century to the 1870s), the recent historical geology stage (from the 1870s to the mid 20th century), the modern historical geology stage (from the mid to late 20th century), and contemporary historical geology stage (21st century onward). The course of historical geology development, globally and in China, are briefly reviewed stage by stage. This paper also presents the opinion that historical geology research in the 21st century should, firstly, attach great importance to the integration and overlap of different disciplinesnot only to the integration and overlap between historical geology and other branches of Earth sciences, but also to that between historical geology and other disciplines, including social sciences; secondly, pay more attention to the study of Earth sphere interactions, understanding and recognizing various geological phenomena as records and products of interactions among Earth spheres and among the Earth and other planets; and thirdly, focus on the study of global environmental changes in each geologic period, allowing historical geology research to facilitate a harmonious coexistence of manking and nature, and transform historical geology from merely an Earth science discipline to a crossdiscipline of Earth and social sciences.

Key words: historical geology, Earth system science, history of science and technology