Traditional Chinese Medicine (TCM), originating from oriental philosophy and culture, has been developing through a series of special research and experiments with meditation, accumulation of experiences, and a complete comprehension of ancient theories and methods. However, compared with Conventional Western Medicine (CWM), the theory of TCM is complicated and not easily accepted by Westerners. It is important to explore TCM by using modern scientific techniques and theories. Utilizing his frontier experience and up-to-date scientific knowledge, Dr. Qian Xuesen has been trying to incorporate some key principles with the comprehensive understanding of TCM and clarify difficult but important concepts and principles. Some examples are the existence of invisible matter; 'Qi' and 'Qi monism'; the Heart representing the 'whole will' of human beings; the water environment functioning as a fundamental condition of life; the human body being united with nature and universe as one; the spirit and physical body always being considered unified and connected with the five viscera, especially with the Heart; and the Chinese herbal formula working with different principles than CWM drugs. These works are important for understanding the essence of TCM, the promoting of the modernization of TCM theories by means of the latest of achievements in scientific developments, establishing the direction for future medicines with TCM characteristics, uniting Chinese and Western medicines, and exploiting a bright future for the health of mankind.