LAVINIA MADALINA MICU, ILARE BORDEASU, MIRCEA OCTAVIAN POPOVICIU A NEW MODEL FOR THE EQUATION DESCRIBING THE CAVITATION MEAN DEPTH EROSION RATE CURVE Paper present a new relation describing the curve MDER(t) which mediates the experimentally obtained values of the mean depth erosion rates. These curves are used to characterize the cavitation erosion behavioor of materials tested in the Cavitation Laboratory of Timisoara Polytechnic University. Practically the new relation is an improvement of the analytical model established in 2004 by Bordeasu and coworkers, by introducing a supplementary element, which take into consideration the shape of the zone in where the cavitation erosion rate became stable and has linear variation. These addition allow increasing the approximation of the experimental values and also putting into evidence the tiny differences between different materials (various types of stainless steels, highly alloyed bronzes etc.) which till now were considered with similar resistance. Thus, the supplementary term allow a better differentiation resulting from the chemical composition, the structure and the mechanical properties.