Secondary relaxations of low density polyethylene-poly(vinyl chloride) blends with various proportions of components (1:9, 1:1 and 9:1 w/w) were studied by photoluminescence of anthracene molecules dissolved in the bulk polymer. The temperatures of the relaxation processes were determined by the ratio of the vibronic components of the fluorescence band on the temperature. The molecular mechanism of this relaxation involves motions of short segments of the polymer chains. These blends show phase separation in the solid state which is observed by fluorescence optical microscopy. It is also noted that the distribution of anthracene molecules in the blends is not homogeneous and it is mostly concentrated in the polyethylene domains.315467474