| There is a special structure in modern Chinese. From the point of structure, they often are made of two coordinate parts which have the same structure and the number of characters. From the point of meaning, the most of symmetric structure have a pair of morphemes or words which have the connection of near-synonym, antonymy and synonymity.The two are closely connected and must appear at the same time. Sometimes the relation of two parts of the symmetric structures are transition,continuation and causality and effect etc. The structure is called as the symmetric structure.This text trys to use cognitive linguistics and categorization theory to analyze the symmetric structure from the point of three plane theory of Chinese grammar.There are combination symmetric structure whose meaning is just simple adding of their two parts and amalgamation symmetric structure whose meaning is more than their simple adding of their two parts but has new meaning. Amalgamation symmetric structure is the studying object of this text.The semantic analysis of the symmetric structure can be taken into account from five aspects which are the relationship of A,X ,B and Y,the relationship of AX and BY, syntax structure meaning of the symmetric structure, the semantic cognitive feature of the symmetric structure, concrete meaning of the symmetric structure in concrete context, and the semantic of syntax function.The syntax function of the symmetric structure has difference between categorization and decategorization. The categorization symmetric structure can be a sentence independently and the function is identical with the function of its two parts. But the function of decategorization isn't identical with the function of its two parts, for example, nominal structure often can be adverbial and verb structure often can be attribute.The function of the symmetric structure from the point of pragmatic has four aspects which are the agility structure of the symmetric structure, the simple vivid and natural visualize meaning of the symmetric structure, the beauty of rhythm and music because of the symmetric of its two parts,extending the function of pragmatic to make a sentence.There is no the symmetric structure in English, but from the point of rhetoric, if the meaning of AX and BY are antonomy we can compare the Chinese antitheses rhetoric with the English antithesis rhetoric. |