We consider the reflection of non-polarized radiation from the point-like sources above the accretion discs both the optically thick and optically thin. We investigate the dependence of the polarization of reflected radiation on the aperture angle of incident radiation. The aperture angle is determined by the radius of accretion disc and the height of the source above the disc. For optically thick accretion discs we show that, if the aperture angle is smaller 70 grad, then the wave electric field oscillations of reflected radiation are parallel to the accretion disc plane. For aperture angle greater than 70 grad the electric field oscillations are parallel to the plane "normal to accretion disc -the line of sight". The latter also holds for reflection from the optically thin accretion disc independent of the aperture angle value.The black holes (BH) demonstrate the presence of accretion discs both optically thick and optically thin. About 300 supermassive black holes (SMBH) exist in active galactic nuclei (AGN). There are ∼ 20 BH in X-ray stellar binary systems ( see Cherepashchuk 2006).The observed linear polarization from (AGN) in Seyfert galaxies frequently demonstrate two types of polarization. In the first type the wave electric field E-oscillations are parallel to the plane of accretion disc. In the second type the E-oscillations are parallel to the plane (nN), where N is the normal to the disc plane and n is the line of sight. It appears the same effect is in X-ray binary systems ( see, for example, Fabrika 2004 and references therein). The most often observed polarization is parallel to the disc plane. In Seyfert-1 AGNs the polarization frequently corresponds to oscillations in the plane (nN), but there are polarizations with intermediate values of position angles. Note that the measurement of linear polarization from AGN is one of very effective technique to obtain the information about the structure of AGN. The polarimetric results are given in many papers (see, for example, Impey et al.