This research analyzed the expression trend about the slit which composes the open space by the visual concept and then introduced the imbedded aesthetic value in it. Based on it, this work aims at showing the evidence on the slit as a utilizing tool for various design applications and providing the basic materials in order to develop the creative design production in the fashion area in the future. Specifically, for the theoretical background in this research, the concept of slit and its chronological changes were reviewed through literature. For the empirical analysis on the slit, a total of 226 designs with its application were analyzed from collection pieces in the four major collections including Paris, Milan, New York, and London from 2006S/S to 2012S/S. As a result of analysis, types of slit appeared as a slash, opening, slit, or a mix of them. These were applied to many different items of clothing, and among which, one-piece or dress was adopted most for application. In regard to space form, perpendicularity was used most frequently. But other various forms like cross and geometrical pattern were also used as well as curve, oblique line and horizontality. As to the arrangement of slit, single type was most frequently used. However, in addition to it, other types were also applied, producing both the functionality and the decorative detail such as bilateral symmetry, free irregularity, and a combination of regular and repeated layout which makes an effect of single pattern. Aesthetic values imbedded in slit were revealed as functionality, sensuality, spatiality, and decorativeness.