The Qieyun 切韵 "Cut rhymes" is the oldest surviving dictionary arranging characters according to pronunciation. It was written by Lu Fayan 陆法言 during theSui period 隋 (581-618).

The pronunciation of the characters is indicated by the so-called fanqie system 反切 ("reverse cuts"). It came up during the period of the Southern and Northern dynasties 南北朝 (300~600) when the changing shapes of characters (from seal script to chancery script), changing pronuncation and the treatment of foreign texts in shape of Buddhist writings made it necessary to render the standard pronunciation in written form. Two older books using the principle of rhymes, Li Deng's 李登 Shenglei 声类 and Lü Jing's 吕静 Yunji 韵集, from the Three Kingdoms 三国 (220-280) resp. the Jin period 晋 (265-420), are lost.

The Qieyun was finished in 601. The original is lost. Only a manuscript fragment is preserved that was unearthed in Dunhuang 敦煌, and fragments quoted in other books. In the last decades a lot of manuscript fragments from the Tang period 唐 (618-907) came to light which make it possible to understand the general structure of the book. The Qieyun consisted of 8 juan "scrolls" and included 11,500 characters, arranged in 193 rhyme groups (yun 韵). 53 rhyme groups are level tone rhymes (pingsheng 平声), 51 falling-rising tone rhymes (shangsheng 上声), 56 falling tone rhymes (qusheng 去声), and 32 entering tone rhymes (rusheng 入声). The first three categories are arranged in a fixed sequence. Below the rhyme group level, the characters are arranged in groups of homophones. Below first character of such a homophones paragraph the pronunciation is indicated by the fanqie system, and the number of homophones. The meaning of the characters is explained with very few words, and many common characters do not have such an explanation at all – the Qieyun thus served often only to render the correct pronunciaton of a character. For a lot of characters an alternative pronunciation is indicated (you yin X 又音Ｘ "also pronounced X"). Later revisions have enlarged the dictionary by missing characters and standardized the entries by the addition of missing definition, etc. These are the so-called cengdingben 曾订本. Sometimes even the pronunciation notes are modernized by using other characters for the fanqie system. Some rhyme groups have been split up in two groups. The greatest change in this respect was made by the Tang period scholar Wang Renxu 王仁昫 in his Kanmiu buque Qieyun 刊谬补缺切韵. There are two revised editions of the Qieyun of good quality, one is Wang Renxu's edition, stored in the Imperial Palace Museum 故宫博物院, the other is Chen Pengnian's 陈彭年 Da-Song chongxiu Guangyun 大宋重修广韵 from the Northern Song period 北宋 (960-1126).

There was another book called Qieyun, compiled by the Tang period scholar Li Zhou 李舟. The book is lost but it is known that its arrangement of the rhyme groups influenced later rhyme dictionaries.