This is paper, a group of synonyms ‘Benlai’ and ‘Yuanlai’ as the research object, respectively, from the syntax, semantics and cognitive linguistics that describes and discusses, analyzing their simliarites and differences. This article is focused on synonyms ‘Benlai’ and ‘Yuanlai’ have their own meanings, while some have their own meanings. In theory, synonyms have the same meaning and can be replaced in context, and the more frequently used side becomes the basic meaning. In this sense, ‘Benlai’ is regarded as the basic meaning, and ‘Yuanlai’ is considered the basic meaning of change. When synonym ‘Benlai’ and ‘Yuanlai’ are used as adjectives, even if the same central noun aremodelled, ‘Benlai’ is used as modifier, as shown by differences in the meaning of the sentence, while ‘Yuanlai’ is used as modifier the central noun is characterized by change. This can also be seen ‘Benlai’ and ‘Yuanlai’ are used as adverbs. In a basic sense, extended ‘Benlai’ means that it should be logically done, which implies the subjective viewpoint of the speaker. ‘Yuanlai’ extends to subjectivity, which are much more powerful than the subjectivity of ‘Benlai’ and events led by the speaker are vividly expressed to express surprise and unexpected. Synonyms ‘Benlai’ and ‘Yuanlai’ have essentially ‘past’, but can be used respectively in permanent attributes or sentences aimed at change, which cause a difference in subjectivity from cognitive perspective.