漢語詞彙發展的歷史，最重要的一項演變，就是從上古漢語的單音節詞，演化為中古漢語的雙音節詞，這種演化的痕跡，反映在各種文獻資料當中.其中數量最龐大反映雙音化的痕跡最明顯的就是佛經的語料了。從東漢以來，佛教傳入中國，大量的佛經被翻譯成中文，一直到唐代達於高潮。前後數百年之間，翻譯了數千卷的佛經，而這些佛經都是用當時的口語譯寫出來的。因此現在保留的二十多部大藏經資料，保存了中古漢語十分完整的口語材料，成為漢語語言學中了解中古詞彙發展的最重要憑藉。從現存的佛經資料當中，我們可以很明顯的看出來，漢語從單音節走向複音節(bisyllabification)的脈絡痕跡。音節複合的過渡階段，人們會做多種的嘗試，然後經歷了選擇淘汰、約定俗成，逐漸的選擇了雙音節詞成為漢語構詞的主流。

The most important development of Chinese language is the change of monosyllabic in the ancient period into bisyllabic ones in the medieval era. Such a change can be found in a variety of written works， among which the linguistic data elicited from Buddhist texts provide most evidence of the bisyllabification process. Since the Eastern Han Dynasty， when Buddhism was introduced into China， a large amount of Buddhist texts were translated into Chinese; this trend reached its apex during the Tang Dynasty. During the span of hundreds of years， thousands of volumes were translated via dictation. The existing 20 plus volumes of the Tripitaka fully preserve the oral data of the Chinese language in medieval times and can thus serve as the most vital channel to comprehend the development of lexicon structure in Chinese linguistics at that time. The bisyllabification in Chinese language can be easily proven by the existing Buddhist texts; the transition underwent diverse attempts by people or by their habits of langua use， gradually leading to the mainstream bisyllabic system for Chinese morphology.