Abstract: [Purpose/Significance] Source disciplines are the disciplines that export knowledge to an inter-discipline, and is the foundation and important driving force for the interdisciplinary development. This paper aims to explore the interdisciplinary development mechanism through linking the development process of the inter-discipline with the structure and changes of source disciplines. [Design/Methodology] Taking Computational Linguistics（CL）as an example, based on the articles and references of CL in Web of Science database, this paper quantitatively describes the structure, characteristics, levels and changes of the source disciplines in the development of CL, and then makes a qualitative analysis in combination with the development characteristics of CL. [Findings/Conclusion] The knowledge structure of the Inter-discipline is revealed by cluster analysis of source disciplines. Source disciplines can be divided into leading disciplines, important disciplines and general disciplines, while the leading disciplines play an important role in the interdisciplinary development, and the distribution and changes of important disciplines in different periods reflect the expansion and changes of main knowledge sources of the Inter-discipline. The interdisciplinary development is completed in the process of cooperation and competition among leading disciplines, which may lead to the paradigm shift of the inter-discipline. [Originality/Value] Based on the measurement of "potential energy of source discipline", the source disciplines are divided into three different levels; through the analysis of the cooperation and competition between the source disciplines in the interdisciplinary development, the internal development mechanism of the Inter-discipline and the possibility of paradigm shift is revealed.

Key words: Inter-discipline, Source discipline, Computational linguistics, Potential energy of source discipline, Leading source discipline, Paradigm shift