This paper has a social semiotic approach and, using multimodal discourse analysis, analyzes the discourses of modern art museums in today’s society. Mainly drawing on the theories of discourse and multimodality, the author aims at answering her research question: How multiple communicative modes help communicate the discourses of modern art museums, and how they are applied in order to increase a museum’s cultural capital and to grow its power as an institution? The paper concludes that multiple discourses of the modern art museums are communicated through combinations of various visual modes, such as color, image, text, sign and layout, where each mode complements each other. These modes are applied when creating museums’ visual and graphic profile, for example, when designing a logotype, signage system, stationery, website and posters, color scheme and even museums’ exterior and interior.