Wideband radars have particular advantages in aspects of antijamming, object identification and tracking. In this paper, the characteristics of wideband radar sea clutter are analyzed based on the rough surface scattering model. Firstly, the twodimensional ocean rough surface is built by using PM spectral function, and the tapered incident wave is applied to eliminate the edge diffraction. Afterwards, the wideband radar clutter amplitude of scattering cell can be obtained by using the physical optics (PO) scattering model and subband synthesis. Finally, the wideband radar clutter echoes are modeled and simulated. The spectrum characteristic and high resolution range profile (HRRP) of the sea clutter are achieved. The impacts of bandwidth, grazing angle and wind speed on the characteristics of sea clutter are analyzed respectively. The simulation results show that radar band width increase and the grazing angle decrease while the echoes amptitude of sea clutter have a significant decline. Meancohile the inpact of wind speed is not obvious.