Abstract: Just as literary criticism of ethics indicates, literature is the product of morality, "literature is the unique expressional form of ethical concepts and moral life in a specific period of history, and literature is essentially art of ethics".In his fiction, Kurt Vonnegut, the renowned American contemporary fictionist, deeply concerned about human existence and fate in the postmodern times or the post-industrial society or late capitalism, insists on utilizing the ethic of ecological postmodernism that recognizes differences, promotes mutual tolerance, and harmonious co-existence of all the component parts of the universe, for establishing ecological social ideology, constructing extended families that can save human beings, and resuming the interconnection and wholeness of man and man, man and the world. Vonnegut further emphasizes the ethical spirit of ecological postmodernism for man living in the agglomerate culture, aiming at reconstructing a democratic, harmonious, and ecological human society in which all lives care for and love each other. The postmodern ethic that runs through Vonnegut's fiction has an important epistemological value and realistic meaning for promoting human beings to advance ceaselessly towards a healthy, ecologically sustainable society.