“X不比Y·Z”是个歧义句式,包含三种语义类型:Ⅰ．陈述差异,Ⅱ．陈述差距,Ⅲ．否定差距。本文认为,类型Ⅰ是宋代以来汉语中一直存在的;类型Ⅱ是五四前后在外语特别是英法德俄等语言的推动下通过功能扩展产生的;类型Ⅲ是在英法德俄等外语的直接影响下产生的。 “X is not worse than Y. Z” is an ambiguous sentence that contains three types of semantics: Ⅰ. State differences, Ⅱ. Statement of gaps, Ⅲ. Negative difference. This paper argues that type I was always existed in the Chinese since the Song Dynasty. Type II was produced by functional extensions under the impetus of foreign languages, especially in the English, French, German and Russian languages ​​before and after the May Fourth Movement. Type III was directly influenced by foreign languages ​​such as Anglo-German, Russian and Russian Produced under