'1-2-3D instalation' is a conceptual work that brings the basic elements of one-dimentional & two dimentional formative elements into three-dimensional space. It's designed focusing on creating a constructivist sculptural aesthetic. In particular, this work has started with the intersection and combination of lines on a two-dimensional plane and thought about how points and lines can interact in a three-dimensional space. In other words, it is an exploration of the image that can be shown when one-dimensional, two-dimensional, and three-dimensional sculptural elements are harmonized and organized in a three-dimensional environment. Based on the experiments on the sculptural elements, various visualizations were proposed through 3D sketches, and it is an installation sculpture experiment designed in a form that can be displayed in an exhibition hall.