When was the earliest Chinese dictionary? What book was written? Who created it and when? It is the earliest dictionary in Chinese history.

Erya is the earliest Chinese book explaining the meaning of words and a dictionary in ancient China. "Erya" is also one of the Confucian classics and is included in the Thirteen Classics. Among them, "er" means nearly upright; "ya" means "elegant language", which is the official normative language of a certain era. "Erya" is the language that makes the language close to the official regulations. "Erya" is a work for later generations to examine ancient words.

Its authors have always had different opinions. Some think it was made by Confucius' disciples, and some think it was made by Zhou Gong and improved by later generations. Most later generations believe that it was made by people in the Qin and Han Dynasties. It was passed down from generation to generation, each with its own improvement, and was compiled and processed in the Western Han Dynasty.

Ban Gu recorded 20 articles in 3 volumes of "Erya" in "Hanshu·Yiwenzhi". After the Tang Dynasty, it was included in the "Jingbu" and became one of the Confucian classics. There are 19 extant chapters in Erya, which is different from the 20 chapters mentioned by Ban Gu. Some people think that this is mainly due to the different methods of dividing the chapters, while Song Xiangfeng of the Qing Dynasty believed that it was caused by the loss of an original "preface".