Professor Chai-sung Lee, Who had introduced the chemical engineering discipline for the first time into this country, is retiring from Seoul National University at the end of August this year. As the very pioneer of the chemical engineering profession in Korea, he has been serving in various aspects and capacities for the development of the profession. It was by him that the formal chemical engineering curriculum was established at Seoul National University early in 1950’s. He was also the man who give birth to the Korean Institute of Chemical Engineers in 1962. It was through his leadership that the Third Pacific Chemical Engineers’ Congress, held at Seoul in 1983, was a great success and ever since it became a model for an international academic conference in Korea. During his tenure of 43years at Seoul National University, perhaps the longest in the history of the University, he has surely set a standard not only as a teacher but also as a researcher that can hardly be surpassed. He also served as the Dean of Engineering for four years late in 1970’s to make major contributions toward the development of engineer-ing discipline. It is now only natural that we dedicate a special issue of Hwahak Konghak in honor of Professor Chai-sung Lee on this occasion of his retirement from Seoul National University, in recognition of his dedication to the development of the chemical engineering profession. He is now retiring but it is only from the professorship. All of us are quite certain that Professor Lee’s professional activities will not be affected at all to make him as busy as ever.