Material feminism, with Barad’s material agency, Alaimo’s trans-corporeality and Benett’s thing power as its key concepts, advocates that the material-discursive practices form the agency of matter, nature and human bodies. The transmission of toxins among different kinds of bodies shows the trans-corporeality between the human body and its environment. Material feminism proposes the trans-corporeal ethic which encourages treatment of environment with strategies and precaution. With its own vision of nature, body and environmental ethics, material feminism is an important environmental theory which leads to the fourth wave of American ecocriticism.