Like other river dolphins, the Baiji has a very long, narrow beak with a slightly upturned tip and with 30-36 teeth per side of both the upper and lower jaws. The small eyes are placed high up on the face.

The Baiji are usually found in pairs, which aggregate often to form larger social units of about 10 individuals.

In the turbid waters of the Yangtze, vision is mostly useless and the Baiji have poor eyesight, but use a highly developed echolocation for navigation and to find food.

The major factors causing the decline of the Baiji in recent years is illegal fishing using electricity, which has accounted for 40 percent of known deaths, and especially water pollution and the construction of dams and floodgates that block fish migration in the river's tributaries and lakes.