In this paper, the effects of using conventional KLtransform and dip scanning stack KLtransform to remove coherent noises in seismic record are discussed, with their scopes of application and limitations pointed out. Based on these two methods, the authors suggest a new technique for removing coherent noises, which is called space-time variety and dip angle KLtransform. With this technique, we can not only remove the strong coherent noises effectively but also maintain the continuity of effective events. The validity of this technique has been proved by applying it to the synthetic data and the real data.