The electrical properties of a complex of polyaniline with poly-2-acrylamido-2-methyl-1-propanesulfonic acid (PANI-PAMPSA) and composites based on it with the addition of silicon nanocrystals (nc-Si) ranging in size from 30 nm to 100 nm are studied in this article. It was found that the dc conductivity of PANI-PAMSA decreases with the introduction of nc-Si. Investigations of alternating current showed that the frequency dependence of the conductivity of the polymer and composites based on it obeys the Jonscher law, which indicates a significant role of the hopping mechanism of conductivity. A mechanism of PANI-PAMPSA conductivity reducing by incorporation of silicon nanocrystals is proposed. The mechanism is associated with energy distribution of localized states in the band gap of the polymer changing and is independent of the nc-Si synthesis method. Keywords: polyaniline, silicon nanoparticles, conductivity, nanocomposites.