Abstract: In the application of high-power lasers, damage of coating multilayers of laser systems mainly limits the laser performance, so there is great interest in reducing the susceptibility of optical coating damage. In this paper, defects of HfO2/SiO2 high reflected coatings and their laser damage have been studied in details. The coating samples were deposited by e-beam evaporation onto K9 glass substrates using hafnia-silica materials. The defects and damage morphologies of coating were observed and analyzed by AFM, Normaski and SEM microscopes. In damage experiment, it was found that the coating onset damage is mainly caused by nodular defect. The laser energy density for damaging the pits, flat bottom pits etc is more three times than that for damaging nodular(about 15J/cm2). The size and it