College of Geo-exploration Science and Technology��Jilin University��Changchun 130026��China

The marine controlled- source electromagnetic (MCSEM) method is a low frequency electromagnet- ic subsurface surveying technique�� The existence of the seafloor noise often seriously influenced the MCSEM follow- up inversion and interpretation�� In this paper�� we reviewed the MCSEM noise characteristics and traditional Bilater- al Filtering method��and proposed time- varying Bilateral Filtering method on the basis of the traditional Bilateral Filtering method and MCSEM noise features��and applied this method into MCSEM data processing�� Through the processing of synthetic model and field data��the result shows that the MCSEM noise can be well suppressed by the time- varying Bilateral Filtering method��especially for the middle- long and long offset area noise��which improved the MCSEM data quality for follow- up processing��