Damage experiments on TiO2 and ZrO2 coatings show that the thresholds of coatings induced by single or multiple shots increase monotonically as absorption of the coatings decreased. The main factor for inducing damage of coatings is the absorption of the coatings, including inherent absorption and that created by the coating inhomegeneities. Damage of coatings induced by multiple shots shows some accumulative effect of micro-damages.