This study is on the eco-art from two dimensions, intentional and unintentional. As the cases of unintentional eco-art, the summer and winter ceremonies of Kwakiutl on west of Canada, written by Eric Wolf, and the winter ceremony Smila(Spiritual Dance) and related dances of Chehalis Indian Band are being considered. Unintentional conceptualization and realization as eco-art are investigated. The other one is on the intentional trials in contemporary societies for the integration of ecology and art. Cases of ‘performing nature’ are interpreted. Maehyang ceremony in Muan-gun tidal flat and related dance are considered. Rituals of Kwakiutl and Chehalis tell dances, as essences of rituals and as the subjects of expressions and communications, exist. The dances exist as the arts realizing relations between natural beings and human beings, realizing the transformation of natural beings, of human beings, of relations between human beings. Ecological relation between nature and man are realized from the immediate feeling and perception of bodily experience. The meanings of the relation are also produced from the feeling and perception. The term and concept of eco-art do not exist in these rituals. But realizing process of ecological relation and interaction is also the one of eco-art unintentionally. Body and dance are main subject and mediate of the process. Recently eco-art, the term has been used by some scholars and artists. But, in many cases the term is not used actually realizing eco-art. Some trials of modern art as ‘performing nature’, Maehyang ritual and dance as reinvented one composed of partial ideas from trasitional one are those realizing the issues and ideologies intentionally. As common phenomena in the two dimensions eco-art expresses ecological ‘relations’, not merely depicting nature. Commonly too, materiality of body and things on nature and human life, feelings and perception of them form the ecological relation.