In this paper, a male Baiji (Lipotes vexillifer) was trained by the method of operant conditioning to learn a series of actions, including listening to sound, hand-touching, accepting stroke, lying on side, lying on back, etc. The general rules of learning the above actions were analysed and some mental phenomena of the Baiji during the learning process were discussed. The Baiji had a strong ability for long-term memory and showed some cognitive ability in certain aspects. The method for training Baiji for some actions is useful for studying the learning capability of the Baiji.
