Initially, people did research on the background, meaning, status and significance of the theoretical system of socialism with Chinese characteristics from the political perspective. And then, the focus was shifted to its theoretical foundation, theoretical themes, theoretical origin, developmental process, logical structure and content frame from the academic perspective. Today, the fundamentals of this theoretical system should be further refined from the theoretical, systematic and popular perspectives. The research of the fundamentals of this theoretical system should be made by means of abstraction and generalization, the combination of theory and practice, and the integration of history and logic. The basic standards to judge the fundamentals of socialism with Chinese characteristics include digging up, analyzing and refining the basic, stable, universal, highly abstract, and logical fundamentals from large amounts of theoretical achievements, policies and measures concerning the concepts, arguments and views of this theoretical system by means of abstraction and generalization. In view of the philosophical method, only those which can solve the basic problems occurring in the practice of socialist construction with Chinese characteristics, play the guiding role in the practice of socialist construction with Chinese characteristics, and have been proved to be the true core theories by practice, can be enhanced as fundamentals. The fundamentals of the theoretical system of socialism with Chinese characteristics can only be extracted from the law of historical development of socialism with Chinese characteristics.