Learning dictionaries play a very important guiding role in learning both mother tongue and foreign language. Since 1980s, English learning dictionaries for non-English learners have developed continuously, and five advanced English learning dictionaries with different characteristics have been published. Namely Oxford Advanced Learning Dictionary, Longman Dictionary of Contemporary English, CBLLINS Cobuild Dictionary of Advanced English, Cambridge Dictionary of Advanced English and Macmillan Dictionary of Advanced English. These dictionaries aim at the needs of users, actively absorb the research results of modern linguistics, and with the support of large corpora, they are based on practicality and constantly bring forth the new, showing strong vitality and setting a good example for dictionary compilation in other languages.

The compilation of learning Chinese dictionaries started late in China, and there are two types at present:

Like the English learning dictionary, an "export-oriented" learning dictionary for foreign learners whose mother tongue is not Chinese, which is written for the purpose of improving Chinese proficiency, is customarily called a Chinese learning dictionary for foreigners. Lv Shuxiang's Eight Hundred Words of Modern Chinese (Commercial Press, 1980) is the first dictionary of modern Chinese usage in China, which is mainly used by non-Han people to learn Chinese and can also be used as a reference for ordinary Chinese workers. Since then, dictionaries for learning Chinese as a foreign language have come out one after another: Modern Chinese Learning Dictionary (edited by Sun Quanzhou, 1995), Modern Chinese Usage Dictionary (edited by Li Yimin, 1995), Modern Chinese Learning Dictionary (edited by Xu Yumin, 2005), and Chinese Learning Dictionary of Business Library (.

The other is an "introverted" learning dictionary for native Chinese learners, which aims to improve their native Chinese language ability, such as the Dictionary of Modern Chinese Difficult Words edited by Li (Commercial Press, 1999). The Dictionary of Applied Chinese, edited by Guo (Commercial Press, 2000), pays attention to the use of words, and has made some useful attempts in part-of-speech tagging, word meaning analysis, word-formation tips, illustrations and so on, and has already possessed some main elements of an introverted learning dictionary. This time, on this basis, we developed and compiled the Modern Chinese Learning Dictionary.