The dynamical properties of three-dimensional non-hydrostatic and ageostrophic inertial-gravity waves, such as polarization and wave-activity relation, are examined.It is shown that inertial-gravity wave processes elliptical polarization between any two ve locity components.The phase difference between disturbed pressure and vertical velocity is.The phase difference between disturbed potential temperature and disturbed vertical velocity, the same as that between disturbed horizontal divergence and disturbed vertical vorticity, is (2n+1)π/2.