本研究以台語／ian／韻兩个變體做主題，探討這个韻咧台灣ê語音變化。這馬咱台語ê／ian／韻會當聽著兩款變體〔-ien〕 kap 〔-en〕。毋過咧清代韻書內底，攏屬咧有介音ê〈軒堅〉韻。另外閣有一个倚〔-en〕讀ê〈丹干〉韻，但是若就發音ê角度來看〈丹干〉韻kap〔-en〕是無關係ê。對遮ê線索，咱通推論講／ian／韻ê變體〔-en〕是現代才出現ê，本文以／ian／韻做主題，掠1900-1960年出世ê人做研究ê對象。本文欲探討ê問題有三个：（1）台灣／ian／韻ê兩个變體是按怎競爭ê？（2）咧演變ê過程，敢有啥物特殊ê現象？（3）未來閣是按怎發展？本文使用兩份資料，一份是龔煌城教授（1992、1993、1994、1995、1997）「臺灣地區漢語方言調查計畫」38條語音紀錄，kap馮怡蓁教授（2003）「國台語雙語自發性獨語語料庫」39份音檔，攏總77个發音人ê語音做基礎。本文對／ian／韻介音統計結果發現：／ian／韻介音ê使用有出世年方面ê tsing-tsha。而且，對1930-1950年出世ê發音人，咧腔口方面有那來那明顯ê對立。偏漳腔 對無介音ê方面發展去，偏泉腔是介音ê，毋過老泉腔ê介音比新泉腔ê閣較 穩定。Suà落／ian／韻繼續演變，對1951年以後出世ê發音人，毋論是啥物款ê腔 口，／ian／韻趨向發展去〔-en〕去，而且成做未來ê演變趨勢。總ê來看，／ian／韻ê變化可能受著語音變化當中內部、外部雙方面ê影響，使得未來／ian／韻較強勢 ê是無介音ê 〔-en〕。

This paper studies two varieties of the /ian/ rhyme in Taiwanese (also known as Taiwan Southern Min), [-ien] and [-en]. In the rhyming dictionary of Southern Min-accent, /ian/ belongs to the ＂Hian-kian (軒堅)＂ rhyme with a medial. Meanwhile, there is ＂Tan-Kan (丹干)＂ rhyme, whose phonetic representation is similar to [-en]. According to these facts, we suppose that the [-en] variety of the /ian/ rhyme arisen in the recent time. This study has three research questions: 1) How do the variations of the /ian/ rhyme contend in recent years? 2) In the sound change process, is there any particular phenomenon? 3) Which variations will be the prestige one? The paper analyzed the data of 77 subjects in total from two data sets. The results suggest that ago group and dialect have gradually become a significant factor, particularly for those born between 1930 and 1950. The Tsaing dialect tends to not have the medial, yet the Tsuânn doesn't. Furthermore, the old accent of Tsuânn is more stably utilized than the new one. For those born after 1951, whose phonetic representation of /ian/ rhyme prefer to be [-en]. Lastly, the [-en] variety of the /ian/ rhyme seems to become popular in the near future. In other words, [-en] becomes more and more prestige in two varieties of /ian/ rhyme in Taiwanese in the foreseeable future