Abstract：Surface wave is a severe noise wave in land seismic exploration. It must be suppressed before stack in order to improve the signal/noise ratio and resolution of seismic data. Ordinary surface wave elimination methods were developed usually on the frequency and apparent velocity characteristics of surface wave，and bring positive effect in practice. However，these methods damage effective waves in some degree because they only lay particular emphasis on a single characteristic of surface wave or are based on a theoretic mathematic hypothesis.By describing detailedly the surface wave field in mathematic principle，we developed a new method for wave field conversion and separation，which has been used to desirably separate off surface wave field and effective wave field. The new method suppresses surface wave satisfactorily;and it also avoids the loss of effectine wavy energy (particTlarly, low frequency energy)，preserves the frequency band width of signal，and raises the signal/noise ratio of seismic data. Real data results show that it is a quite good method for prestack surface wave suppression.
