‘Electromagnetic Fields and Waves’ is an important professional basic course for students in the major of electrical and electronic engineering. Students regard it as the most difficult course because of numerous concepts and equations. Philosophy could assist the students’ understanding of the electromagnetic theories. The Chinese Yin- Yang principle reveals the basic composition and operating principles of the universe from the macroscopic and microscopic view, which provides another way to illustrate the electromagnetic phenomenon and equations. This paper presents a heuristic teaching practice carried out by combining the Chinese Yin- Yang principle and modern electromagnetic theory. Several lectures on vector analysis, electrostatic field, steady magnetic field, time-varying electromagnetic field, and gravitational field, even relativity and particle theories are given to show the application of the Yin- Yang principle. Student survey and exam results show that the adoption of Yin-Yang principle could help students to acquire the basic concepts in limited teaching hours and to promote philosophical thinking embodied in China's university education.