The years between the 1920s and the 1960s saw a transformation of chemistry in several aspects. These included the development of biochemistry, polymer chemistry, quantum chemistry, and computational chemistry, as well as the instrumental revolution. New methods, theories, and technologies opened up new fields of chemical sciences, and the chemical industry grew to be one of the most important branches of industry that supported national economies. Chemistry was greatly influenced by World War II and the Cold War, when it was directed especially to military and security needs, while the public image of chemistry also changed, due largely to the environmental problems caused by synthetic chemical materials. These years also saw developments in Japanese chemistry. The first generation of Japanese chemists started their research in the early 20th century. Born and educated after the Meiji Restoration, the starting point of Japan’s full-fledged modernization, some of them founded a research strategy that aimed to study the structure of components of Japan’s local natural products using methods newly developed in Europe, in order to compete with chemists in the West. However, after several decades, the accomplishments of seven Japanese Nobel laureates in chemistry became not fundamentally different from those of their Western counterparts. Their researches, performed mostly from the 1950s to the 1970s, developed new methods and theories and opened new fields. Clearly, there must have been a transformation of chemistry research in Japan between the 1920s and the 1960s as well. The aim of the workshop “Transformation of Chemistry from the 1920s to the 1960s” is to stimulate a discussion of the transformation of chemistry in Japan and/or in the world during the period with comparative perspectives. The workshop may take an interdisciplinary approach and pay special attention to the social dimension of chemistry. This subject has only recently started to be discussed and even then it has only been considered intermittently. This workshop attempts to bring those interested in the history of chemistry in the 20th century together for dialogue and debate from various perspectives. It will comprise thematic four keynote lectures, sessions with papers and commentaries, and a concluding general discussion.