Abstract: Combining the rotating vector method， the constructed process of the beat phenomenon and

the rea- son that caused the characteristic of the Beat phenomenon are analyzed. Then the

amplitude and the phase position of the beat phenomenon are discussed in detail. Finally， the

phase jump is also shown by the rotating vector method

clearly. The method describing the beat phenomenon in this paper makes the model of the beat

phenomenon so visu-al and intuitive that one can understand it very easily.

Key words: beat phenomenon, rotating vector, period, intuition