In the research, the writer found that there are two types of language style in the talk show the tonight with Jay Leno, such as formal and casual style where casual style most dominant in the talk show. Besides that, there are four functions through the speaker's utterances, those are : expressive, directive, metalinguistic and referential function where referential function is most dominant in the talk show. It can be concluded that in the talk show the people ofthen use casual style and referential function because to make a comfortable situation and effective understanding of the conversation.