本文旨在研究中古庶民吳音，《顏氏家訓．音辭篇》云：「易服而與之談，南方士庶，數言可辯；隔垣而聽其語，北方朝野，終日難分」，知金陵士庶語音有別，然今所見之原本《玉篇》、《經典釋文》切語，均紀錄士族雅言，罕有代表庶民吳音者也。今考中古庶民吳音材料，得宋郭茂倩《樂府詩集．清商曲辭》收錄〈吳聲歌曲〉共四百二十二首詩，其中八十首為文士擬作，題有作者；其餘三百四十二首詩作者不詳，或題晉宋齊辭，乃民歌也。吳歌約起於東吳，迄於晚唐，恰中古之世，其不詳作者之三百四十二首民歌，正足以代表庶民吳音。今整理吳歌韻字，較諸《切韻》，論其分合，可得中古庶民吳音分韻之梗概也。

The thesis analyzes common people's phonology of Wu dialect in Middle Chinese. According to Yanshi Jiaxun (The Family Instructions of Master Yan), the chapter of phonology suggests ＂In the south, phonological rules differentiate between intellectuals and common people even with different garments; however, even eavesdropping through the wall all day, hardly can listeners distinguish between stratums by phonological rules.＂ The quote manifests the clear phonological difference between intellectuals and common people in Jin Ling. Yet in Middle Chinese dictionary, Yupian (The Jade Chapters), as well as the textual explanations of classics, Jingdian Shiwen, common people's phonology of Wu dialect is rarely seen, compared to detailed record of phonology of clans of scholar gentry. Delving into the texts of common people's Wu dialect in Middle Chinese, 422 Wu-Ge ballads were found in the chapter of Qing Shang Quci in Anthology of Yuefu Poetry, compiled by Guo Maoqian in Song Dynasty. 80 of them were created by literati, with writer's name listed respectively; while 342 poems were of unknown authorship or given title of Jin Song Qi Ci, suggesting characteristics of ballads. Wu-Ge has been developed between Eastern Wu and Late Tang Dynasty, equivalent to the era of Middle Chinese. The 342 poems of unknown authorship can best represent the phonology ofWu dialect. From researched Wu-Ge rhyming rules and compared with Middle Chinese rime dictionary, Qieyun, we can understand phonology of Middle Chinese Wu dialect.