本文討論郭店與上博楚簡諸篇陽聲韻部通假字組的音韻關f系，並與漢以前 傳世詩歌文獻的合韻現象相互參證'對異部通假的音韻條件提出我們的看法。 具體討論真文、文元、真元、耕真、耕陽、東陽、冬東、冬侵、蒸侵、侵談...... 等跨韻部的通假。陽聲韻部的跨韻部通假，有與對轉的陰聲韻平行者，仔服日: 陰聲有脂微，陽聲有真文;陰聲有微歌，陽聲有文元;陰聲有支脂，陽聲有耕 真;陰聲有侯魚，陽聲有東陽。也有不與對轉的陰聲韻平行者，例如:耕陽、 蒸侵、侵談、冬侵......等。 主要申詰命有:相異韻部的通假與合韻現象反映韻部的異讀層次;單一音系 的上古音構擬無法解釋紛繁的異部通假或合韻;真元、文元、冬陽、蒸陽、侵 談的通假或合韻，凸領真、文、冬、蒸、侵應該具有低元音的音讀層次，與 中、高元音的音讀層次共存於上古漢語-m 、n 、。鼻音韻尾韻部間的通 假，是頁示上古音存在鼻化韻的音讀層次，與J陰陽主持專的陽聲韻情形相同。

This paper investigates the interchangeable characters in certain Chu bamboo slips of Guodian and Shangbo and the rhyming phenomena of some poetry from ancient time , and , by doing so , tries to clarify some questions about the rhyme system in the Archaic Chinese with the help of the stratum analysis in historicallinguistics. This paper shows that a study of the interchangeable characters in these texts can help 個solve some long standing problems concerning the interchangeability of characters and rhyme merger. This paper will specifically discuss the interchangeability of characters from the nasal-ended rhyme division. The primary conclusion of this paper is that the interchangeability of diHerent divisions and rhyme merger are the result of convergence of readings from diHerent strata. A reading stratum can reflect a time period , an area, or a historical change The interchangeability of diHerent divisions and rhyme merger indicates that the rhyme divisions zhen ( 真) ，抖，閱(文)， Dong ( 冬)， Geng ( 耕) , Zeng ( 蒸) and Qin (侵) should have a low vowel stratum. The switch of the vowel/ stop-ended rhymes and the nasal-ended rhymes that occurs in the interchangeable characters and rhyme merger arises from a nasalized rhyme stratum.