The calculation method of seawater density by the multi-angle and polarized information was advanced here.The function between the properties of polarization of seawater and the seawater density was inferred from the angle of multi-angle remote sensing and polarized remote sensing.The seawater density was calculated by the polarized property of seawater and refraction index of seawater.The work will be helpful to extend the available application scope of remote sensing and exploit a new idea of ocean basic parameters' inversion.