Abstract: On the basis of moving source radiation theory,this paper discusses the sound solution of a rotating source in frequency domain.Emphasis is laid on near sound field which has three additional sources in contrast to far field.The computation reveals that the near sound field produced by these "additional sources" distributes in discrete viewing angles.Radial and axial deviations affect sound field respectively around the rotating plane and axial area,and their maximum connections have different characteristics.The analysis is proved preliminarily by a fan experiment.