本文首先論述傳統服制中「親親」一詞主要指有血緣關係的親屬，因此「嫂叔」不得以「親親」視之，並論「嫂叔無服」實因二人來往密切而制訂。其次討論傳統服制中「嫂叔無服」的相關規定，以及蔣濟、成粲、曹羲等人藉由改讀經典、混淆經典用語或以「人情」為理據等方式，倡議「嫂叔有服」。復次討論「嫂叔服議」在此時被提出討論的原因，包括〈喪服〉篇的流傳、門閥制度興起以及戰亂、疾病對社會思潮的影響，此部分為本文重點所在。最末略論提出「嫂叔服議」者和玄學中倡議「自然」者的關係，認為二者面對同樣的時代因素，卻分別採用不同的應對策略，提出服議者針對「名教」進行改革，而非站在其對立面。

Owing to the absence of words or phrases in English, this summary uses transliteration to translate the concept of the mourning practice between younger brother and elder sister in law, which are ＂saoshuwufu＂ (嫂叔無服) and ＂saoshuyoufu＂ (嫂叔有服) and ＂saoshufuyi＂ (嫂叔服議). This article start with the discussion of the meaning of ＂qin qin＂ (親親), which mainly refers to the blood relatives in the traditional mourning system. Therefore, the relationship between elder sister and younger brother in law shall not be considered as ＂qin qin＂. Furthermore, because of their frequent intercourse, they shall not mourn for each other. Secondly, discussing the relevant provisions of saoshuwufu (嫂叔無服) in traditional mourning system, Jiang Ji, Cheng Can, Cao Xi who proposed ＂saoshuyoufu＂ by re-interpretation of the classics, or claim that there are profound emotions between younger brother and elder sister in law. Thirdly, expounding the reason why the mourning practice between younger brother and elder sister in law had been put forward in Wei Jin dynasty. The reason including the circulating of ＂Sangfu＂, the prospering of family institution, and the influence of war and disease to social thoughts. This section is the most important part of this article. The last part of the article focuses on researching the connection between people who proposed saoshufuyi (嫂叔服議) and the advocates of nature in metaphysics. The two groups faced the same period factor but adopted different strategies, the former reformed feudal ethics rites, instead of confronting the rites.