Abstract This work presents a mathematical model describing the cavitation erosion of materials. The model of cavitation erosion is based on Weibull's distribution. The model describes the influence of material properties i.e. relative resistance to plastic deformation and the stress intensity factor of the hardened surface layer under cavitation loading on the cavitation erosion of materials. A new factor describing the cavitation erosion resistance of materials is proposed. The new coefficient R is a function of incubation time, maximum volume loss rate v max and time after which v max follows. The factor permits to evaluate materials according to their cavitation resistance. In addition, there is a possibility to define the influence of mechanical properties on the cavitation resistance, upon the base of the new factor values.