Abstract: The liquid/solid erosion wear tests were conducted for 3Cr13 steel which had been tempered at different temperatures on the self-made jet-type erosion wear tester.The effects of microstructure on erosion behavior of 3Cr13 steel were investigated,and erosion mechanisms were also discussed.Results showed that for all the three tempered microstructures of 3Cr13 steel,maximum erosion rates were found at 45 degree angle of attack.The erosion resistance of specimens tempered at 200 ℃ and 500 ℃ exhibited no obvious difference,showing better erosion resistance than the specimen tempered at 750 ℃ which reached stable erosion stage earlier.The main erosion mechanism was characterized by micro-cutting at low angle of attack and by brittle spalling and fatigue damage at high angle of attack.