Although English rhetorical devices often violate the Cooperative Principle, it generally doesn’t impede the speakers to communicate. Listeners can understand the speakers’ conversational implicature based on the Cooperative Principle and the specific context. This paper analyzed the rhetorical devices violating the Cooperative Principle from the perspective of Grice’s Cooperative Principle. Although English rhetorical devices often violate the Cooperative Principle, it generally does not impede the speakers to communicate. Listeners can understand the speakers’ conversational implicature based on the Cooperative Principle and the specific context. This paper analyzed the rhetorical devices violating the Cooperative Principle from the perspective of Grice’s Cooperative Principle.