The three major theoretical schools of sociology are: doctrine, sociological positivistic, and theoretical structuralism. The theory of the school of Marxian theory is an important school of sociological theory. Its basic idea is "historical realism", which believes that society is the objective reflection of material existence, and the development of society is determined by the interaction and influence of economic foundation and the upper structure. The main characteristics of the school of theory of the theory of the The theory of sociological positivistic theory was a sociological theory that attached importance to the study of positivistic research and the laws of social reality. Its main idea was that "positivistic" believed that only by doing positive research could a real scientific conclusion be drawn. Theory must be linked to reality for positive research to verify or overthrow the theory. The main characteristics of sociological positivistic theory include: emphasizing the importance of positive research, emphasizing the validity of theory, and thinking that theory must be connected with reality for positive research. The theory of theoretical construction is a sociological theory that values the free creation and construction of theories. Its main idea was that "structuralism" believed that theory was the creation and explanation of reality by human beings, and that theory was formed in the process of continuous development and evolution. The main characteristics of the theory of theoretical construction include: emphasizing the free creation of theory and the significance of theoretical construction, paying attention to the historical and cultural background of theory, and believing that theory is constantly developing and evolving. The difference between the three schools of theory was that the school of theory of the Marxists mainly focused on the objective and materialistic nature of society, emphasizing the regularity and universal nature of the development of social history; the school of theory of sociological positivistic theory mainly focused on the positive research and the law of social reality, emphasizing the validity of theory; the school of theory of theory construction mainly focused on the free creation of theory and the significance of theoretical construction, emphasizing the historical and cultural background of theory and the significance of continuous development and evolution of theory.