Electromagnetic scattering from rough sea surfaces with a ship-induced Kelvin wake is investigated by utilizing the polarimetirc scattering model of second-order small-slope approximation with tapered wave incidence. The emphasis is on the examination of the effect of ship-induce wake on bisatic scattering signatures of rough sea surfaces, since the presence of ship-induced wake may significantly change sea surface's geometric structures especially for low wind conditions. Numerical simulations also show that the scattering signatures of rough sea surface is significantly influenced by ship-induced wake, which is of great importance for the detection of ships in marine environment.