本文在系统功能语言学理论框架下探讨语言系统的分形特征及其功能变异。我们首先回顾分形的要义，并阐释分形机制之于系统功能语言学范畴化的方法论意义。然后，我们从分形视角重新考察系统功能语言学中的一些核心概念，分析分形在语言系统中的运作机制。研究发现，分形是语言系统内的功能变异机制，在语言的个体发展、历时进化和即时生成中承担关键作用。最后，本文探讨语言系统分形的社会符号学基础及其对语篇研究的参考意义。

THIS paper investigates the fractal features and functional variation of the language system from the perspective of Systemic Functional Linguistics (SFL). It first reviews the concepts of fractal and fractalization, elaborating on their significance as part of the SFL methodology in terms of categorization. Then, it reexamines some key concepts in SFL from the fractal viewpoint, analyzing the working mechanism of language fractalization. It is found that fractalization creates functional variation within the language system; also, fractalization plays a significant role in ontogenesis, phylogenesis and logogenesis. Finally, this paper discusses the social semiotic basis of fractalization of the language system and its implications to discourse studies.