The Kangxi zidian 康熙字典 "Dictionary of the Kangxi reign (1662-1722)" is the largest character dictionary of traditional China. It was compiled on imperial order by Zhang Yushu 張玉書 and Chen Yanjing 陳延敬 and was finished in 1716. These Qing period 清 (1644-1911) compilers made use of older dictionaries, expecially the Ming period 明 (1368-1644) dictionaries Zihui 字彙 by Mei Yingzuo 梅膺祚 and Zhengzitong 正字通 by Zhang Zilie 張自烈. It consists of 12 "collections" (ji 集) of which each is divided into three parts. It makes use of the 214 radicals system established in the Zhengzitong. Each character is attributed to a radical. The radicals are arranged according to the number of brush strokes. Below the radical levels characters are arranged according to the stroke number left after subtracting the radical. The Kangxi zidian contains 47,035 characters and was the largest dictionary before the compilation of the Zhonghua da zidian 中華大字典 in 1915. This large number comes into being because all character variants from ancient times on are recorded. For each one the locus classicus is quoted. A long introductory part explains the use of the traditional rhymes (Zimu qieyun yaofa 字母切韻要法). There is also an index for characters whose radical is not easy to determine (Jianzi 檢字) and a chapter comparing characters that are very similar to each other and not easy to discern (Biansi 辨似).
For each character the pronunciation according to the fanqie system 反切 is given first, as it is explained in older dictionaries, like the Guangyun 廣韻, Jiyun 集韻 or Gujin yunhui 古今韻會, and then the direct pronunciation (zhiyin 直音) via a homophonous character. The pronunciation paragraph is followed by an explanatory part in which quotations from all kinds of literature is given to explain the different meanings of the character, in first place often from the oldest character dictionary of China, the Shuowen jiezi 說文解字, followed by the Confucian classics, historiographic writings, and on to belles-lettres. This part is often followed by a section rendering alternativ readings, alternative meanings, and alternative writings of the character.
The quality of the entries is very high compared to older dictionaries, as the Kangxi zidian is very critical to a lot of quotations. There were, nevertheless, errors in the quotations, for which reason Wang Yinzhi 王引之 compiled a text-critial appendix to the dictionary, the Zidian kaozheng 字典考證, in 12 chapters (juan "scrolls"). It contains 2,588 paragraphs of corrected mistakes. Another critical appendix to the Kangxi zidian has been written by the Japanese scholar Watanabe Atsushi 渡部温, the Kangxi zidian kaoyi zhengwu 康熙字典考異正誤, which contains 11,700 entries.
Sources: Zhou Shiqi 周女琦 (1988). "Kangxi zidian 康熙字典", in: Zhongguo da baike quanshu 中國大百科全書, Yuyan wenzi 語言文字, p. 236. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.
Chen Bingcai 陳秉才 (1990). "Kangxi zidian 康熙字典", in: Zhongguo da baike quanshu 中國大百科全書, Xinwen chuban 新聞出版, p. 180. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.