  The photoionization cross-sections of two even-parity excited states, $5d6d
^3D_1$ and $6s7d ^3D_{2}$, of atomic Ba at the ionization-laser wavelength of
556.6 nm were measured. We found that the total cross-section depends on the
relative polarization of the atoms and the ionization-laser light. With
density-matrix algebra, we show that, in general, there are at most three
parameters in the photoionization cross-section. Some of these parameters are
determined in this work. We also present the measurement of the radiative
lifetime of five even-parity excited states of barium.
