语言中的否定表达具有负确定性质,并且容易产生歧义。根据否定标记的实际使用情况,有构词否定、短语否定、句子否定三个层级。文章提出“否定常数”(NT)这一概念,它是句子否定在文本小句中的百分比。对小说《红楼梦》的统计揭示出汉语中的否定常数为15%左右。文章还就否定表达的消极语言态度做了一些文本分析。 Negative expressions in language have negative deterministic properties and are prone to ambiguity. According to the actual usage of negative mark, there are three levels of denial of formation, negative phrase and negative sentence. The article proposes the notion of “negative constant” (NT), which is the percentage of sentence denials in text clauses. The statistics of the novel “Dream of Red Mansions” reveal that the negative constant in Chinese is about 15%. The article also made some textual analysis on the negative language attitude of negative expression.