本文主要探討虛詞「廼」由殷卜辭過渡至西周金文在用法及構詞上的歷時變化。透過二批材料的對比分析，發現殷卜辭「廼」字僅用作時間副詞，發展到西周金文除承襲殷卜辭副詞的用法之外，更發展出了連詞的用法。另外，就構詞而言，殷卜辭的複合結構「先〜廼〜」、,「於〜廼〜」不見於西周金文；而西周金文「廼〜廼〜」結構亦不見於殷卜辭。整體來看，「廼」字西周金文的用法及講詞均較殷卜辭更加虛化、複雜而靈活。

The study is to analyze the changes in usage and formation of the function word “Nai(廼)” in Oracle Bone Inscriptions and Bronze Inscriptions. Materials from both Inscriptions have been compared and analyzed, and it shows that “Nai(廼)”is used only as a time adverb in Oracle Bone Inscriptions, while in Bronze Inscriptions, it is not only used as a time adverb but also conjunction. The study also finds that, in terms of formation, the compound sentence pattern “Xisn(先)〜Mai(廼)〜”and “Yu(于)〜Nai(廼)〜”only exist in Oracle Bone Inscriptions, while “Nai(廼)〜Nai(廼)〜” can only be seen in Bronze Inscriptions. According to the findings, the function word “Nai(廼)”in Bronze Inscriptions is more complicated and flexible in its usage and formation.