《切韵》支、脂等八个三等韵存在着重纽,重纽分为A、B两类。这八个三等韵的喉牙唇音字中哪些字归重纽A类,哪些字归重纽B类,学术界一般都没有异议,但是少数字的归类仍有分歧。本文提出归字的五种方法,并对“鬐、螼”等十多个字的归类作了讨论。 “Cut rhyme” branch, fat and other three three rhyme there are important New York, New York is divided into A, B two categories. These eight third-rhyme throat lip sound words which belong to the category of New York, which words belong to category B, the academic community generally have no objection, but the classification of the few figures are still divided. This article puts forward five methods of returning words and discusses the classification of more than ten words such as “鬐, 螼”.