For some issues of common interest in specialty course teaching for undergraduate students majored in engineering, Tsien's thought on modern scientific and technological systems is adopted, and the viewpoint of "three-incorporation" in teaching, i.e., the incorporation of scientific common basis and special engineering problems, the incorporation of scientific principles and experiences or commonsense in daily life and industrial production, and the incorporation of qualitative concepts and quantitative methodologies, is proposed. The idea is illustrated by taking the teaching of the undergraduate course of loads and structural design principles as an example.