Abstract: The cavitation erosion resistance behavior of several fiber reinforced composites(FRP) were investigated by using an ultrasonic experimental cavitation facility. By experiments on the relationship between mass loss rate and erosion time, and the relationship between mass loss and the erosion time. If the erosion condition was controled and keeped unchanged, the erosion ability of the material could be judged by observing the relationship between the mass loss and time. The erosion resistance effects of several reinforced materials on composites sample was:glass fiber > aramid fiber > glass fiber ribbon fabric > carbon fiber ribbon fabric.