I am honored to have been called upon to help establish the Zhou-Pei-Yuan Center for Applied Mathematics, after retirement twice from academic service. I feel humbled and also apprehensive of the task ahead. I would like to make use of this opportunity to say something about my understanding of applied mathematics.

Applied Mathematics consists of two words: 'applied' and 'mathematics'. In general, Applied Mathematics also include two areas. One area is the Mathematics related to Application. This a subset of traditional mathematics. The other area is the Application of Mathematics, i.e., the study and solution of scientific and engineering problems using mainly mathematics as the tool. This is not a subset of the traditional mathematics and is beyond traditional mathematics. The Zhou-Pei-Yuan Center for Applied Mathematics will emphasize the latter area of applied mathematics.

The past development of applied mathematics in China, including Tsinghua, has almost entirely concentrated on the former area, i.e., Mathematics related to application. They have achieved notable accomplishments. However, there is general lack of endeavor to going deep into scientific and engineering problems by Chinese applied mathematicians so far. Hopefully, the establishment of Zhou-Pei-Yuan Center for Applied Mathematics will help remedy the deficiency on this aspect.

Of course, many scientists and engineers are using mathematics as tool to tackle problems in their respective disciplines. They are indeed applied mathematicians, except that they do not have such label formally attached to them. Center for applied mathematics offer a home, when they want to be so labeled, to work and interact closely with other applied mathematicians in various scientific disciplines. Indeed, there are many such scientists and engineers who, because of personal inclination, general interest, working environment, or a desire to gain more mathematical nourishments, would like to work in a home with the label of applied mathematics.

This kind of applied mathematics is necessarily inter-disciplinary. Zhou-Pei-Yuan Center for Applied Mathematics will thus necessarily be an OPEN center, interacting and collaborating with other departments in Tsinghua. We shall interact not only with scientists and engineers in Tsinghua, but also beyond Tsinghua, beyond Beijing, and beyond China. Here we have such a promised land. We invite you all to join exploring and developing.

Fifty years ago, when I was still a college student in Taiwan, Dr. Hu Shih came back from America to give a series of lectures. He referred to his participation and leading the May Fourth New Cultural Movement as a kind of 'sowing the seeds'. I am now following Professor C C Lin to establish the Zhou-Pei-Yuan Center for Applied Mathematics, is also a kind of 'sowing the seeds'. We sincerely expect you to help it to blossom and bear fruits.