Edward Albee's The American Dream is a moral fable about ethical taboos. The ethical crimes appeared in that play reveals the existence of Sphinx factors in people's mind and its complexity: the mutual collide and transformation between “human factor” and “animal factor” actually show the ethical conflict among rational will, free will and irrational will. The play centers on a “loveless marriage” and the natural emotion of characters: because of the weakness of ethical consciousness, those characters driven by their natural emotion to “kill child and abuse mother”, thus, which causes the breakdown of consanguinity relationship and goes against the human ethical taboos that has already been formed for ages, consequently, their behavior lead to a serious ethical crisis. The main reason why they dare to blatantly violate the ethical taboos is that they are all controlled by irrational will and lose their rational will, so they make their ethical choices wrongly and execute ethical crimes. This paper uses Ethical Literary Criticism as its research perspective, and it focuses on “kill child and abuse mother”, the core event of ethic in that play, meanwhile, it probes a series of ethical propositions, which are caused by this ethical event, such as responsibility, obligation, filial piety, mercy, fear, despair, killing, suicide and so on. What's more, it reveals the ethical purport of Albee's drama creation: through writing the extreme moral behaviors in American family life and the damage these behaviors have made to those family members, Albee attempts to awaken people's attention of familial affection and their maintenance of family ethical order.