Chinese is different from other major languages in type. Compared to Indian and European languages, Chinese has lack of morphological changes in the strict sense, but the adverbs in Chinese are very rich and the function can equal the morphological changes in Indian and European languages to some extent. Modal adverbs as a small kind of adverb also has these characteristics.“倒”is a high frequent used modal adverb in Chinese and it hasn’t the corresponding word completely in other languages. How to understand and master the meaning and usage of the adverbs will be the key to master Chinese. So I make a study of the word“倒”.In this paper, I investigate the semantics, syntax and pragmatics of the word“倒”.Firstly, I made a research of the word’s semantics. After studied the tone of some meanings, I got the word’s basic meaning is that things turn to the oppsite of those expected. Other meanings are derived from the basic one. At the same time, I got five kinds of semantic format in reference to Mazhen’s analytical model of“反而”after lots of studies in the word’s background, format and analysis of many matierals.Secondly, I made an investigation of the syntax of“倒”.I studied it from syntactic elements, sentence types of distribution, patterns and a total of syntax. In syntactic constituent,“倒”is usually used as adverbial before verbs. If there are several adverbs in the sentence,“倒”is always in a high position. In clause type of istribution,“倒”can be found in declarative, interrogative, imperative and exclamatory sentences. In sentence,“倒”can be used in sentences whose pradicate are verbs, adjective and subject-predicate. But it cannot be used in sentences whose pradicate are nouns or nothing.“倒”also has a wide usage in complex sentences such as opposite, concessive, side by side, selecting, progressive, assumptions and causal sentences.“倒”can be modified single verb and adjective, it can also be modified verb phrase and adjective phrase and the subject-predicate phrase. It can also be the adverbial element used together with other adverbs.Thirdly, in pragmatic aspects, I made a study in“倒”’s subjective characteristics, tone adjustment function, inferred functions, features and information communicated chapter and link function with the guide of the modern theory of functional linguistic. Overall,“倒”is a subjective commentary of adverb, it has strong subjective and regulation, infer, communicate and chapter functions related to the oppesite of those expected.