Based on the relevant theory, this paper makes an analysis of humor in Chinese popular art form --sketch. It is believed that the maximal relevance and the optimal relevance of utterances, explicature and implicature of utterances, and the efforts made by hearers in dealing with utterances are three important aspects in showing humorous effects in sketches, among which sketch actors＇ violating the mutual cognitive environment so as to create an unexpected effect on hearers is the core in creating humor in sketches. Through analyzing some excerpts from the sketch Yesterday.Today.Tomorrow, the author tries to explore the relevance nature of language in sketch and creation of humor in it.
