Advertising can be regarded as a means of persuading consumers to take action with respect to products, ideas or services. It is a complex phenomenon because it involves two interacting processes, namely, communication and persuasion, and both processes are many-faceted. When advertisers intend to make the advertisement language creative and inventive, they use language different from the linguistic norm. Being unconventional, the advertisements which adopt deviation can give the readers unexpected surprise and make a strong impression on their mind. This kind of language phenomenon is technically called linguistic deviation. Then based on some scholars’ classifications, the author classifies different deviations in advertising (deviation of phonology, graphology, lexicon, and grammar) and illustrates each deviation with some typical examples.