Abstract: The behavior of the Changjiang finless porpoises, Neophocaena phocaenoides, in a net cirele and pools were recorded and analyzed. Its adaptation time to rearing was related to greatuess of the changes of the environmnt and the population structure. The greater the environment and population structure changed, the slower the adaptation, and vice versa. Mother and offspring or one mature female and one mature male often moved together which was core unit of the school composition.The animals showed cooperation behavior, conflict behavior, and play behavior, etc.Mothers refused to care non-offspring. The animals were afraid of narrow channels.