The effect of amplification of photoluminescence of cationic polymethine dyes in the photoconducting polymer films of poly-N-epoxypropylcarbazole, poly-N-vinylcarbazole in comparison with non-photoconducting polymers - polyethylene, polyvinyl alcohol, polyvinylbutyral, and polystyrene were discovered. Such effect is absent for anionic and neutral dyes. The amplification PL increases with a decrease of wave length of excitation light and increase of energy of the highest occupied molecular orbital of a dye. This effect correlates with growth of a photoconductivity, a quenching of PL and a recombination luminescence by an external electric field. The amplification PL is interpreted by the contribution to it of a recombination luminescence of charges in photogenerated electron-hole pairs. The features of a structure PEPC and PVC, favouring to formation and recombination of these pairs are analysed.