In recent years, there is a lot of interest to synthesis of nanostructures as carriers for drug delivery. These structures are considered as a highly effective drug delivery system due to controlling drug release, protecting the pharmaceutical molecule, and environmentally friendly. In this study, the synthesis of chitosan nanoparticles was carried out by chemical method. The nanoparticles size was measured by dynamic light scattering (DLS). Also, it was used from atomic absorption spectrometry (AAS), FTIR and transmission electron microscopy (TEM) to confirm the loading of antibiotic onto nanoparticles and to calculate the percentage of the drug loaded. In addition, it was used from clarithromycin as antibiotic. The antibacterial activity was studied by the disc-diffusion method and the effect of different co The antibacterial activity was studied ncentrations of drug in nano-carriers was investigated and it was determined the optimum antibacterial activity of drug nanocarrier was happened in concentration 0.6 gr/10 ml. پرونده مقاله