본 연구는 요코오 타다노리(橫尾忠則)의 조형이미지를 분석하고 변천과정에 관한 연구를 한다. 그는 1960년대 일본의 디자인에 새로운 충격을 주며 등장한 이후 현재에 이르기까지 독특한 작품세계를 구축해 내고 있다. 그의 작품 세계를 시대별로 분석함으로써, 역사적 상황에 의하여 작품의 조형 이미지가 형성되는 과정들을 예측해 보고, 그 결과가 갖는 현실적 의미를 찾는 데에 목적을 두고 있다. 조형 이미지의 분석을 위하여 먼저 시대별로 작업의 특징을 공시적으로 파악하고, 그것을 통하여 요코오 타다노리의 작품 속에 내재된 조형 언어를 통시적인 방법으로, 요코오 타다노리 자신의 인생을 작품 속에 표현하는 과정을 연구한다. 그 범위는 1965년 첫 작품을 발표한 것을 시작으로 하여 현재까지 약 40년간을 네 개의 기간으로 나누고 작품에 나타난 특징을 고찰하여, 이에 영향을 끼친 사회문화적 배경을 도출해 내려 한다.요코오 타다노리는 직관에 의존한 작업을 하기보다는, 역사적 흐름 속에서 치밀하게 기획된 작업을 전개시켜 왔으며, 새로운 시도에도 적극적이었다. 이러한 작업의 방향성은 디자인에서의 포스트모더니즘이 어떻게 전개되고 있는지도 설명해주고 있다.또한 이 연구를 통해서 모더니즘의 구성주의적인 카테고리 안에서 디자인의 원류를 찾으려는 방식으로부터 벗어나, 다양한 사고와 방법론에 의한 작품읽기의 또 다른 가능성을 제시하고자 한다.This study presents an investigation into the works of Tadanori Yokoo, who made a sensationalize in Japan in the 1960s and has successfully created his own artistic world representing the Japanese design community. Following the developments of his works in certain historical situations, the study focused on the patterns of his potential structures being formed and on the realistic implications of his works. In an attempt to review his formative language, whose consistency was hard to find because of serious formative changes, a synchronic approach was taken toward his works and then a diachronic one was applied to read his own formative language. The ultimate goal was to understand how an artist would work on his works throughout his life. Although his whole life was taken into account, the time period for the study was limited 40 years or so from 1965 when his first work was created to the present times. Among the various kinds of works, his posters were selected to find out what were the overall characteristics of his design and what elements worked to affect his works. In dividing the time period of 40 years, continuation of certain characteristics made the standard rather than a mechanical division. The findings reveal that Yokoo didn't depend on insight for artistic creations but prepared himself thoroughly with strict planning and incorporated his work into the historical flow. He was never afraid of making another challenge. His work style well explains how postmodernism has been evolved in the field of design. The study findings will hopefully provide an opportunity to overcome the still active trend of searching for design source within the category of modernist constructivism and thus to initiate a new movement to appreciate a work through wide thinking and interpretations. It will be also rewarding to see visual design of new authorism make another step into the future.