Foul and abusive language (Liyu) in sociolinguistics refers to taboo (“bad language”) that is associated with swearing or crude expressions such as obscenity, profanity, blasphemy or other cursing utterances that strongly offend the prevalent morality in society of the time. This study attempts to evaluate the semantic and pragmatic functions of Chinese Liyu in contemporary soceity. Being rife and ubiquitous in both society and cyberspace, nowadays Liyu is increasingly popular among the teenagers. As a fashionable trend, the distinct feature of Liyu is “neutralization”. Namely, it has to be neutralized either in form or in function when it is actually used. Based on abundance of exemplar expressions obtained from various textual sources, predominantly from the print press and the Internet, this article conducts an in-depth examination of the actual use of Liyu in contemporary Chinese language. Our findings show that, as a means used to indicate a strong emotional expression and moral repugnance, Liyu serves as an ultimate linguistic device for “extreme option”. From the perspective of language standardization, Liyu is defi nitely harmful to language management. In order to prevent it from polluting language, measures should be adopted to ban its unstrained circulation or to provide guidance on its use. On the other hand, we should realize that Liyu is “useful”; its expressive power is unsubstitutional. Therefore, Liyu will not automatically disappear; it would not be eliminated without prudence.