Abstract: The erosion wear of the polyurea elastic coating was investigated on a high-pressure water jet erosion tester. The results show that the polyurea coating had an excellent erosion resistance performance. On the basis of Bitter's erosion theory of ductile materials, the erosion model of polyurea was established. The erosion behaviors of ductile materials at different impact angle and velocity were described. And the erosion law was proposed, which held that the maximal cutting wear was at the impact angle of 30° or so and the maximal deformation wear at the impact angle closed to 90°.