Abstract: Baiji (Lipotes vexillifer),a fresh-water cetacean species inhabited only in China,has been living on the earth for about 25 million years.Its population size has been sharply decreasing during the past twenty years.The population size was estimated about 400 in early 1980s and down to less than 100 in late 1990s.Its habitat has also degraded drastically;it only distributes in the middle and lower reaches of the Yangtze River in China currently.Factors that threat survives of the baiji mainly come from increasingly human activities,including construction of water development projects,over-fishing and water pollution.Conservation strategies and action plans have been highlighted as follows:establishing natural reserve to protect its natural populations and habitats,setting up semi-natural reserve to conduct off-site conservation,and constructing cell or gene library to save its idioplasmic resources.Off-site conservation has been believed the most urgent action.