Abstract: When marine seismic survey vessels acquire data too close to one another in adjacent survey areas, the sound sources can be disturbed, and seismic waves from another seismic vessel can be received in seismic records. It is so-called seismic interference. As both sound sources have similar characteristics, the principal data and interference exhibit similarities in frequency content and amplitude properties in raw shots, so it is very hard to separate the principal data from the seismic interference effectively and therefore it is hard to attenuate the seismic interference easily with conventional data processing methods. On the basis of the principle for attenuating of seismic interference, two methods are described briefly in this paper. The processing effects and resulting method analysis are made in attenuating seismic interference by practical seismic data processing. Practical data processing shows that both methods have obvious processing effects, but they also have some defects and limitations in attenuating seismic interference. Therefore it is extremely important to take proper method according to the characteristics of seismic data in practical application.