This thesis makes a survey on conception of &ldquo / surface&rdquo / in the works of Peter Eisenman. In doing so, the concept of &ldquo / surface&rdquo / is discussed under three titles: &ldquo / Surface&rdquo / as an element of architectural vocabulary (as a formal element), as an analytical tool (as a grammar), and as a diagrammatic tool. Correspondingly, the thesis is intended to examine how &ldquo / surface&rdquo / is conceptualized and handled through the critical readings of Eisenman&rsquo / s writings, and projects are referred in order to support and visualize the discussions. In this context, Eisenman&rsquo / s dissertation, The Formal Basis of Modern Architecture (1963), reveals the definition of architectural surface in relation to the architectural language that is proposed by him. Through the formal analysis of Giuseppe Terragni&rsquo / s building, Casa Guiliani Frigerio, he utilizes surface as an analytical tool. Considering design processes of his projects, as discussed in the book Diagram Diaries (1999), surface becomes a dominant tool for generating architectural form. As a result, in this thesis, surface is evaluated in various aspects (as a formal, analytical and diagrammatic tool) that are essential for understanding of architectural form. In the case of Eisenman, its significance dominates the way of developing his architecture.