词汇化是指一个短语或由句法决定的其他语言单位在语言的发展演变中其自身变成一个稳固词项的过程。本文以汉语中的“所以”、“因此”等介词结构为例,通过对它们词汇化过程的分析,试图揭示词汇化的某些成词动因。 Lexicalization refers to the process by which a phrase or other linguistic unit that is syntactically determined becomes a solid term in its evolution. This paper takes the prepositions of “So ” and “Therefore ” in Chinese as an example. By analyzing their lexicalization process, this paper attempts to reveal some motivations of lexicalization.