The paper deals in detail with the movement and behavior of 6 finless porpoises living in the Swan Oxbow, Hubei province. All these animals were introduced from the Yangtze River or born in the Oxbow in Mar.-May, 1990. The movement characters of the porpoises such as herd home range, movement capabilities, the seasonal change of the movement in the research areas and the environmental factors which influence the movement, as well as their behaviors were described and analysed. The results showed that the Oxbow was suitable very well for the porpoises. We gave a further ecological assessment and rational suggestions for the Baiji Nature Reserve which will be established in this Oxbow. We can also obtain the information for conservation and management of the secondary order protected aquatic mammal by our work.