The triple system with berberine, silver nanoparticles and polymeric matrix was studied optical spectroscopy methods. Silver nanoparticles were synthesized in situ in water solution of branched copolymers Dextran-graft-polyacrylamide. An adding the berberine to a solution of nanoparticles leads to the changes in the absorption spectra: the optical density in the range 370-470 nm decreases and the band shifts to the long-wave region of the spectrum. The quenching of the fluorescence of silver nanoparticles in presence of the berberine molecules has been detected. These spectral changes considered as an evidence of the aggregation processes caused by the berberine.