Abstract: The study of the pre-Qin philosophers is an important part of the Chinese thoughts history. Different from dividing the pre-Qin philosophers into two groups of the conservatives and the progressives or into various schools, this article demonstrates the status and role of the pre-Qin philosophers in great reforms from the Spring and Autumn Period, the Warring States Period to the Qin Dynasty and early Han Dynasty from the aspects of internal unity of ideological and social change, makes it clear that the great reform is the commonality and main line of the thoughts of pre-Qin philosophers, and further explores the four levels of ideological system, the Tao, the methodology, the technique, and the skill; hence, discusses the characteristics of their respective ideas and relationships.

Key words: thoughts of pre-Qin philosophers, reforms, main line, system