「諧聲關係」向來是古音研究的主要憑藉。但大部分的學者，卻未曾清楚地說明自身如何利用諧聲關係，以及採用諧聲關係進行研究的基本假設是什麼。本文試圖提出「諧聲關係」在方法上的運用分成兩個層面：一是建構詞族內部的關聯性，二是建構古音系統音類之間的關聯性。在文章中，並以中古章系的來源以及其他相關問題具體呈現本文的論述目的。

Phonetic series has been the main basis for researche on Old Chinese. Most researchers illustrate clearly neither how they utilize phonetic series themselves nor what the essential hypothesis is in the research of phonetic series. This article aims to divide methodically the usage of phonetic series into two parts: to construct the connections of inner word family; and to construct the connections among the Old Chinese phonetic group. Also, this article presents the origin of the zhang group in middle Chinese and other relative questions.