Abstract: The Baiji, a rare Yangtze species, usually frequents certain sections in the middle and lower reaches of the Yangtze River. Due to the impact of extensive sluicedam building at the lake-river mouths, channel cutoffs of the lower jingjiang, and the Gezhouba Dam project, it caused a change in channel flows and consequent channel erosion in those affected sections, thus undermining the Baiji's habitat. The research and field surveys in 1991 indicate that there was no Baiji in the Yichang-Shashi reach (160 km), and its distribution density was gradually rarefied in the Ochikou-chenglingji reach, and the total population was reduced to less than 150. It is presaged that the planned Three Gorges Project, once completed, could make a more serious impact on those species. Hence, a reserve strategy must be established to protect this endangered species.