The objective of the study is to analyze expressions of modern fashion in relation to design principle of a science theory, fractal geometry, in order to identify various and multi-layered expressions of fashion. As for methodology, the study interprets principle and characteristics of fractal geometry based on literature review in areas of linguistic, philosophy, sociology and science. The research identifies expressive characteristics of fractal through empirical studies, and applies them to fashion in order to analyze how fractal design principles are reflected in modern fashion in terms of form and significance. Fractal aesthetics pursue order, balance, diversity and openness among disorder and insecurity. They are closely related to the function of modern fashion that works as a multi-layered code, instead of being confined to conventional idea about fashion that "functions" as "wear."