Abstract: The erosion-wear experiments on QT500 and 45# steel simulating the actual working conditions were carried out using a disc erosion test-bed.Erosion wearing characteristics of materials were studied with the weight loss method in different sediment concentrations and particle sizes.The mechanism of erosion and the damage rules were probed according to analyses of the surface morphology of QT500.The erosive rate of materials increased with increasing sediment concentration,but was not directly proportional to the increase amount of solid.The erosion of QT500 increased with increasing particle size.The main mechanism of erosion of QT500 was brittle flaking off and fatigue damage.