The wear resistance of H400 and NM400 low alloy steels were studied through sliding wear and impact wear tests. The wear morphology, impact toughness and metallographic microstructure of the two materials were analyzed by means of impact testing machine, scanning electron microscope (SEM) and metallographic microscope. The results show that the surface microstructure of H400 and NM400 is martensite, but NM400 has more strip martensite. Under the condition of sliding wear test, NM400 has low wear weight loss and better wear resistance. Under the impact wear test condition, the weight loss of NM400 and H400 is not much different, and they have almost the same wear resistance. Both H400 and NM400 lost 2~3 times as much weight under sliding wear test as under impact wear test.