Dark relaxation during a month of holographic gratings (HG) recorded with differently polarized laser beams ( with linear s-s, p-p, s-p polarizations and with orthogonal C-1 and C-2 polarizations) in an inorganic a-As2S3 film and in an organic W-50 film at room temperature has been experimentally studied. HG periods were 2 m, recording wavelength was 532 nm, readout wavelength was 633 nm. Recording light intensity was 1.76 W/cm2. Self-diffraction efficiency (SDE) was measured during the recording and diffraction efficiency (DE) was mesured during the relaxation studies. The maximal SDE and DE values of 3.0% and 17.3% have been achieved with C-1 and p-p polarizations, respectively, in the a-As2S3 film. The maximal SDE and DE values in the W-50 film were 19% and 16.7% achieved with C-2 polarization. Dark relaxation kinetic was similiar in both materials. Asymmetric oscillations around the average DE level were observed. This average level was close to the initial DE in the case of W-50 film, and it was slightly growing in the case of a-As2S3 film.The root mean square value of oscillations (RMSVO) in both materials strongly depended on recording polarizations. They were growing in the following order: C-1, p-p, C-2. The maximum RMSVO took place in the case of s-s and s-p polarizations for a-As2S3 and W-50 films, respectively. Possible explanations of the observations will be given in the talk.