In this paper, the social system theory of Marxism is applied to analyze the six elements of the curriculum-based ideological and political education system in colleges and universities: educators, objects, content, methods, goals and context of the education and their relationship with each other. Besides, the structure and the functions of the system will also be examined, so as to reveal the internal connection and laws governing the development of the system. On this basis, the four fundamental principles of the social system, namely openness, dynamics, wholeness and hierarchy, are analyzed to promote the building of a new, effective and entirely shaped curriculum-based ideological and political education system with a solid foundation.