Abstract: Qimin Yaoshu is of a strong style of colloquialism in the middle ancient times of China, and many compound words were used. Some compound words are similar or related in meaning, which form into different lexical fields of synonym. These synonyms have the same characteristic in word formation:the two morphemes which constitute the compound word have similar or related meaning when used separately. Those compound words are probably new words created by the linguistic community then, based on existing co-ordinate word formation in the middle ancient times. With the development of Chinese lexicon, these synonymous compound words in Qimin Yaoshu had different endings. Those made up of frequently-used monosyllables or formed with new meanings by the metaphorical mechanism, had a relatively higher frequency of use and stronger vitality. As a result, they were much easier to be developed into general compound words of Chinese. Those which were less used or are more difficult to produce extended metaphorical meaning were more likely to drop out of linguistic communication and became a history in the development of Chinese lexicon.

Key words: Qimin Yaoshu, synonymous compound words, lexical field of synonym, co-ordinate word formation, metaphorical meaning extension