Prof. Julong Deng, a Famous Scholar, the Founder of Grey System Theory, Passed Away Professor Julong Deng, a well-known scholar and the founder of the grey systems theory, died at 12:15, 22nd June, 2013 at the age of 80. Prof. Deng was born in Lianyuan county, Hunan procince in 1933. He graduated in electrical machinery from Huazhong Institute of Technology and became a teaching assistant at the Department of Automatic Control Engineering at the same institute in 1955. Through his academic life, he attached great importance to the learning of math lessons, and was keeping track of new ideas and new discoveries of mathematics and other relevant science fields, which definitely constituted a solid basis for his later engagement in multi-variable system control problem. In 1960s, Deng proposed “Over to the control theory of multivariable system” based on experiments that were operated by controlling the feed system of domestic T61K heavy machine tool. His paper, “Multivariable linear system shunt calibration device of a comprehensive approach”, was published by Acta Automatica Sinica, Vol.3, No.1, in 1965. The former Soviet Union Academy of Sciences introduced a summary of his theory at that time. In early stage of 1970s, “Multivariable system to control” was recognized as a representative methodology at the international conference on control theory in the U.S. In 1965, L. A. Zadeh, professor of the University of California at Berkeley proposed the Fuzzy Sets Theory. Prof. Julong Deng began to pay close attention to the work of Prof. Zadeh, and later served as a member of editorial board of several journals on fuzzy mathematics. In the late 1970s, the tide of reform and opening up was raging like a storm in China. For serving the reform and development, Professor Deng had devoted himself to put more effort in the study of “Economic System prediction and control problems”. In the face of a class of uncertain systems which “Partial information is known, the partial information is unknown”, how to find an effective method to describe its operation behavior and evolution mechanism? Professor Deng and his colleagues had made very difficult but fruitful exploration. In 1982, Prof. Julong Deng published his first paper on Grey Systems Theory, “The Control Problems of Grey Systems”, in Systems & Control Letters, a magazine published by the North-Holland Publishing Company. In the same year, Prof. Julong Deng has published another paper on Grey Systems Theory: “The Control of Grey Systems”, which was published in Chinese, in the Journal of Huazhong Institute of Technology. The publication of these two pioneering papers marked the start of a new intersect discipline: the grey system theory. Prof. R.W. Brockett, the editor-in-chief of Systems & Control Letters at that time and a famous scholar at Harvard University, sent the Anonymous reviewers’ evaluation of The Control Problems of Grey Systems to Prof. Deng, “all content of this article is new, the Grey System, a word belongs to the first”. After the birth of Grey System Theory, it has received positive attention from academic circles at home and abroad and general practitioners immediately. Many famous scholars and experts gave full affirmation and support. A lot of young and middle-aged scholars have joined the Grey System Theory research with great enthusiasm to carry out the theoretical exploration and application research in different fields. Successful application of the Grey System Theory in many fields of science, especially a large number of applications in the process of the country’s economic regionalization and regional development strategy planning research and develop, established its academic position of a novel scientific study quickly in a very short period of time. The vigorous vitality and broad prospects for development of Grey System Theory is also increasingly known by scientists from all kind of disciplines. According to statistics, Prof. Julong Deng’s works were cited 28000 times by scholars both at home and abroad. In 2007, Prof. Julong Deng won the award of founder of Grey System Theory at the first IEEE international conference on grey system and intelligent service. In 2011, Prof. Julong Deng was elected as the honor fellow of the World Organisation of Systems and Cybernetics at The 15th WOSC International Congress on Cybernetics and Systems.