Abstract: The development of arts in the 18th century reached a crucial stage in the Western art history, as it saw the gradual emergence of the modern art system. The system, though not shown in the drastic changes of artistic styles and tastes, was significant for the development of the ideas of arts. Different elements help to build an environment for the institutionalization of arts and to promote the establishment of the modern system of fine arts, and the elements include the institutionalization of art criticism, the emergence of modern art historical methods, and the establishment of Aesthetics as a discipline, as well as the development of modern art institutions such as museums. These developments during the 18th century also prepared for both the legitimacy of the idea of the autonomy of arts and the differentiation of fine arts in the 19th century.

Key words: modern art system, art history, art criticism, aesthetics, autonomy of arts, differentiation