The Department of Mathematics of Tsinghua University was established in 1927. From its foundation to the College and Department Adjustment in 1952 (including the period of National Southwest Associated University), the distinguished mathematicians such as Zheng Zhifan, Xiong Qinglai, Yang Wuzhi, Jiang Zehan, Zhao Fangxiong, and Duan Xuefu had served as Dean of Tsinghua mathematics department. These precursors introduced and adopted most advanced mathematics teaching system around the world at that time. They actively initiated academic research and recruited talented people, and brought the newly founded Tsinghua Mathematics Department into its magnificence in the short 25 years. The magnificence not only lay in that a large number of renowned mathematicians had taught in the Department, including domestic mathematicians like Sun Guangyuan, Zeng Yuanrong, Hu Kunsheng, Xu Baolu, Chen Xingshen, Hua Luogeng, Zhuang Qitai, Min Sihe, Xu Lizhi, Cheng Minde, Wu Xinmou, Wan Zhexian, Feng Kang, Zhou Yulin, etc. Above all, Vice chairman of World Arithmetic Association, French mathematician J.Hadamard and modern Cybernetics founder, American mathematician N.Wiener were invited to the Department in 1935 as Visiting Professors. The magnificence also lay in that not a few elites sprang up in this period: Chen Xingshen (Shiing-Shen Chern), Hua Luogeng (Loo-keng Hua), Wu Daren (Dach-rahn Wu), Zhuang Qitai, Xu Baolu, Ke Zhao. From Tsinghua Mathematics Department, the masters Shiing-Shen Chern and Loo-keng Hua steped to the worldwide stage, and their brilliant achievement has had a profound influence to the contemporary mathematics. After the College and Department Adjustment in 1952, the main part of Mathematics Department merged to Peking University. The research strength left was only Computational Mathematics, with Zhao Fangxiong as its representative. The mathematics teachers grouped into Mathematics Teaching and Research Section, and teaching basic common courses was their primary work. In late 1950s, the Major of Computational Mathematics was founded and began to recruit undergraduate students.

In the time of Reform and Open, the Mathematics Department began to enroll undergraduates in 1977. Moreover, in 1980, the Department of Applied Mathematics was established. The discipline Computational Mathematics was authorized in the first batch to grant doctorate degree in early 1980s and set up Doctor Program of Applied Mathematics in 1985. In 1999, the Department of Applied Mathematics was renamed the Department of Mathematical Sciences, with 3 research groups founded in the same year: Fundamental Mathematics Group, Applied Mathematics, Probability and Statistics Group, Computational Mathematics and Operations Control Group. At present, the Department has a faculty of 77, including 42 professors, 32 associate professors, and 3 lectures. The research areas cover:

Fundamental Mathematics Group: Number Theory and Arithmetic Algebraic Geometry, Algebra and Geometry Representation Theory, Differential Geometry and Mathematical Physics, Functional Analysis and Nonlinear Analysis, Complex Dynamical Systems, Complex Analysis and Harmonic Analysis;

Applied Mathematics, Probability and Statistics Group: Dynamical Systems, Fractal Geometry, Partial Differential Equations and Mathematical Physics, Probability and Statistics and Financial Mathematics;

Computational Mathematics and Operations Research Group: Numerical Algebra, Numerical Solutions of Partial Differential Equations, Combinatorial Optimization, Uncertain Programming, Computational Geophysics.

The Department of Mathematical Sciences is a unit of national first-level key discipline. The Department has two majors, Mathematics and Applied Mathematics, and Mathematics and Physics Basic Science (Mathematics), with an annual enrollment around 100 undergraduate students, 50 graduate students and 7 post-doctors. In 2009, “Mathematics Class of Tsinghua School” was set up for the purpose of cultivating academic talents who are devoted to mathematical research, and about 15 to 20 undergraduates are admitted each year. Beyond that, the department offers university-wide basic common mathematics courses to both undergraduate and graduate students. Every year, more than 20 thousand students select these courses

In 2009, the Center for Mathematical Sciences of Tsinghua University was established. The world-renowned mathematician Shing-Tung Yau was appointed the Director. The Department also engaged Shing-Tung Yau as Chief Professor of “Mathematics Class of Tsinghua School”.

The Department of Mathematical Sciences has close cooperation and exchanges with a number of prestigious universities and institutes around the world. Particularly, since 2000, the Department has broadened the collaboration in teaching and research with experts from French and American universities. The collaboration involves areas of algebraic geometry and number theory, computational mathematics, operations research, probability theory, fractal geometry, dynamical systems, differential geometry, partial differential equations, statistics and so on. In addition, the Department has built up close connection within Tsinghua University with Institute for Advanced Study, Zhou Peiyuan Center for Applied Mathematics, and the Center for Mathematical Sciences. These collaborating linkages promote the teaching, personnel training and research of the Department to a forward position.