On December 3, 2004 (October 22, 2004 in the lunar calendar), Chen Shengshen, the international mathematics master, passed away. Chen Shengshen (October 28, 1911 - December 3, 2004), Han nationality, native of Jiaxing, Zhejiang, Chinese American, international mathematics master, famous educator, foreign academician of the Chinese Academy of Sciences, founder of "Entering the Wonderful Mathematical Garden", and a world-class geometry scientist in the 20th century. He showed his mathematical talent in his youth. During his mathematical career, he made several choices and worked hard to climb, eventually achieving brilliance. His outstanding contributions to overall differential geometry influenced the development of mathematics, and was praised by Yang Zhenning as another milestone figure after Euclid, Gauss, Riemann, and Cardan. He has presided over and founded three major mathematical research institutes, creating a group of world-renowned mathematicians. Famous scholars such as Qiu Chengtong, Wu Wenjun, Liao Shantao, and Zheng Shaoyuan have all studied under Chen Shengshen. Born on October 28, 1911 in Xiushui County, Jiaxing, Zhejiang. He graduated from Xiuzhou Middle School in 1922 and came to Tianjin. He entered Rotary Middle School (now Tianjin Railway No. 1 Middle School) in 1923. He graduated in 1926 and entered the Mathematics Department of Nankai University. He graduated in 1930 with a bachelor's degree. In the same year, he joined Tsinghua University as a teaching assistant. In 1931, he began his graduate studies. He studied projective differential geometry under Sun Guangyuan, a pioneer of Chinese differential geometry. He graduated in 1934 with a master's degree, which was the first mathematics graduate student trained by China. In 1934, he received a scholarship from the Chinese Cultural Education Foundation (one said to be funded by Tsinghua University) and went to study at the University of Hamburg in Germany. He studied under the famous geometer Blaschke and received a doctorate in science in February 1936. When he graduated, there were still scholarships left. In the summer of the same year, he received funding from the Chinese Cultural Foundation, so he moved to Paris, France to study differential geometry with E. Cartan. After leaving France in the summer of 1937 and returning to China through the United States, Chen Sheng served as a professor at Tsinghua University; later, due to the Anti-Japanese War, he moved to Kunming, Yunnan Province, and taught differential geometry at the Southwest Union University, which was formed by Peking University, Tsinghua University, and Nankai University. In 1943, he was invited by the American mathematician O. Veblen to work at the Institute for Advanced Study in Princeton. In the following two years, he completed the most important work of his life: proving the high-dimensional Gauss-Bonnet formula, and constructing the most commonly used Chen representational classes (a class of Chen's features), which laid the foundation for global differential geometry. After the victory of the Anti-Japanese War in 1946, he returned to Shanghai and presided over the work of the Institute of Mathematics of Academia Sinica. In the following two or three years, he trained a group of young topologists. In early 1949, Academia Sinica moved to Taiwan, and Chen Shengshen moved his family to the United States at the invitation of Oppenheimer, director of the Institute for Advanced Study at Princeton. In the summer of 1949, he took over the professorship of E.P. Lane at the University of Chicago; E.P. Lane was the mentor of Chen Shengshen's mentor Sun Guangyuan when he studied in the United States; here he made an important contribution to the revival of differential geometry in the United States. In 1960, Chen Shengshen was appointed as a professor at the University of California, Berkeley, until his retirement in 1980. He was elected to the National Academy of Sciences in 1961 and served as vice president of the American Mathematical Society from 1963 to 1964. An important contribution of Chen Shengshen in his later years was the establishment of the National Mathematical Institute at the University of California, Berkeley, which focused on pure mathematics in 1981. He was the first director. After retiring in 1984, Chen was appointed as an honorary professor at Peking University and then Nankai University. In 1985, he was appointed by the Ministry of Education of the People's Republic of China as the director of the Mathematical Research Institute of Nankai University. In the same year, Nankai University awarded him an honorary doctorate. Since 1986, the Chinese Mathematical Society has established and hosted the "Chen Shengshen Mathematics Award". At 19:14 on December 3, 2004 Beijing time, Chen Shengshen passed away in the General Hospital of Tianjin Medical University. After the news of Mr. Chen's death came, Nankai University fell into grief. Nankai students spontaneously gathered by Xinkai Lake, lit candles, and mourned such a great and noble alumnus. Nankai University set up a mourning hall, and a large number of people came to mourn. The scene was very touching.