摘要：This study is about Eugene O’Neill’s use of "medusation" as an effective metatheatrical device and foremost achievement in his art. Occurring onstage as an unexpected "anagnorisis", the medusation is a traumatic experience that engenders ritual death. This author argues that the medusation is a quintessentially metatheatrical act, insomuch as here O’Neill carries out a commentary on the function and functioning of theatre, through the consciously fictitious events that unfold on the stage. In the "Introduction", the author reviews its development in O’Neill’s plays, from the more traditional melodramatic situations of the early works to the subsequent portrayal of a self-defeating pattern calling for psychological violence and symbolic death. In the section called "Medusation", the author addresses the concept of medusation in order to account for the process whereby O’Neill’s people, annihilated by their sudden glimpses into the other within themselves, undergo major physical and spiritual change. In "Case Studies", the author analyzes the chief correlatives of medusation: the dead-in-life, the death mask and the dead double. The author’s point in this paper is, thus, to show how extensively and pervasively O’Neill deploys medusation in order to signify a rite of passage that engenders metatheatrical death. Its outcome may either be the perpetuation of an endless spiral of violence and self-defeat, or a premise for rebirth arising from the characters’ assumption of responsibility as to their share of guilt in the evil of the world, together with the renewed human sympathy and understanding that this awareness brings along.