The erosion wear behaviors and mechanism of reaction-bonded silicon carbide were studied by jet erosion wear tester and SEM surface analysis in this paper. The results show that the erosive wear rate of reaction-bonded silicon carbide would be increased and then decreased with the increase of erosion angle and would reach the peak value when the erosion angle is at 60º. It is lower than that of high chromium cast iron at all of test erosion angle. The reaction bonded SiC will show better erosion wear behaviors when the SiC particle size matches with the amount of free silicon. The erosion wear mechanism of reaction bonded SiC was analyzed.