Abstract: A detailed comparison of cavitation erosion performance in tap water of five alloys in a vibratory (no flow) and venturi (flow) system has been made. The effects of temperature variation (80 to 200℃) , venturi throat velocity (34 to 49 m/s) , and vibratory horn double amplitude have been studied. Correlationa between maximum erosion rate, MDPRm$x and incubation period, IP, and the material mechanical properties of Brinell hardne:.s, BHN and ultimate resilience, UR ( = UTS2/2E) have been examined. Only moderate success was achieved in correlationz between "erosion resistance", MDPRmax-1 and 1P and these mechanical properties. However, a good correlation was found between MDPRmax and IP, Pertinent to both facilities, of the form MDPR max{sup}-1＝a×（IP）{sup}n, where n is near unity (0.94) . Cavitation intensity, as measured by MDPRmax, was found to be 10 to 20 time greater in the vibratory depending upon horn amplitudc and material. This ratio varies between 5 and 30 if individual materials are considered separately, being greatest for 1018 carbon steel and least for 316 stainless steel. This indicates the important differences in form between these cavitating regimes, and the imprecision of material comparisons measured in either.