Here we present the spectropolarimetric observations of the radio-loud active galaxy 3C 390.3 in the period 2009-2014 (24 epochs). The galaxy has been observed with the 6-m telescope of Special Astrophysical Observatory of the Russian Academy of Science (SAO RAS) using the Spectral Camera with Optical Reducer for Photometric and Interferometric Observations (SCORPIO) spectropolarimeter. We explore the variability and lags in the polarized light of the continuum and broad H{alpha} line. We give the Stokes parameters Q, U, degree of linear polarization P and the position angle of the polarization plane, {phi}, for 24 epochs. We find a small lag (10-40 d) between the unpolarized and polarized continuum that is significantly smaller than the estimated lags for the unpolarized broad emission lines (lag(H{alpha}) ~138-186 and lag(H{beta}) ~60-79 d). This shows that the region of the variable polarized continuum is significantly smaller than the broad line region, indicating that a part of the polarized continuum is coming from the jet. The lag of the polarized light in the H{alpha} line (89-156 d) indicates an additional component to the disc one that has an outflowing velocity of ~-1200 km/s. This region seems to depolarize the polarized broad H{alpha} line emitted from the disc and scattered in the inner part of the torus.