The results of optical absorption study of silver nanocomposites on a basis of arabinogalactan-oligopyrrole block-copolymer matrix with different length of oligopyrrole branches (1, 3, 10 chains), pure polypyrrole and also arabinogalactan that is natural polysaccharide of Siberian larch wood are discussed. Optical absorption study of silver nanocomposites with arabinogalactan-oligopyrrole block-copolymer matrix showed the presence in spectra of three absorption bands that result from arabinogalactan end aldehyde groups, transversal and longitudial components of 0D and 1D nanosilver plasmon absorption. According to transmittance electronic microscopy data, nanocomposite of nanosilver and block-copolymer grafted matrix with unit ratio arabinogalactan-oligopyrrole 1:1 has 73 % of 0D nanoparticles with 21,3 nm mean size and 27 % of 1D nanoparticles with 28,7 nm mean length and 20,9 nm mean width. It was found that width of the arabinogalactan absorption band at 294 nm and plasmon absorption of 0D nanosilver observed for samples with unit ratio arabinogalactan-oligopyrrole 1:1 and 1:3 at 426 and 490 nm respectively increase and become considerably less evident, and the absorption band due to longitudinal component of 1D nanosilver plasmon resonance and polarons of nanocomposite matrix oligopyrrole branches shifts to longer wavelengths with growing the length of oligopyrrole branches (585, 754, 800 nm for the nanocomposite of 1:1 and 1:3 and 1:10, respectively). It was also demonstrated that optical absorption maximum of polypyrrole has long-wavelength shift owing to this conducting polymer passes into weakly doped state under influence of environment air.Keywords: optical absorption, nanocomposites, silver nanoparticles, copolymer matrix, arabinogalactan, conjugated copolymer.