Sonochemical method was used to prepare ultrafine Azithromycin. The morphology and size distribution of the particles prepared were characterized by scanning electron micrograph (SEM) and Zetasizer Nanoinstrument. The chemical bonding of production was examined by Fourier transform infra-red absorption spectroscopy (FT-IR). The result shows that different diameter particles of Azithromycin were prepared, and no fundamental bonding change in the Azithromycin molecule after preparation.