Abstract: In this paper,a male Baiji(Lipotes vexillifer)was trained by the metliod ofoperant 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 oflearning the above actions were analysed and some mental phenomena of the Baijiduring the iearning process were disscused.The Baiji had a strong ability for long-term memory and showed some cognitive ability in certain aspects.The metliod fortraining Baiji for some actions is useful for studying the learning capability of theBaiji.