Erosion of leading edge in wind blades and in helicopter blades leads to a drop in the aerodynamic performance of the blade.Erosion is primarily caused by the repeated impact of solid particles or liquid droplets on the composite surface of wind turbine blades and other composite surfaces.Current approaches to erosion protection involve the application of coatings on composite surfaces.The erosion protection ability of coatings are typically characterized under laboratory erosion test apparatus.A mechanics based erosion prediction model would help to predict erosion under more realistic environment and also make it easier to qualify the effectiveness of various comings based on their mechanical properties.However,little work has been done to understand and develop predictive models for erosion in composites though several models do exist for metal erosion.