Abstract: The erosion experiments of 35CrMo steel with three different hardness and five different impact speeds are carried out, and the weight loss and eroded surface morphology studied and analyzed. The influences of speed and hardness on erosion wear rate of 35CrMo steel are analyzed, and the equation of erosion wear rate with speed and hardness fitted. The experimental results show that the erosion wear rate of 35CrMo steel increases rapidly with the increase of speed, with a power relation of 2.55~2.66, and decreases linearly with the increase of hardness. Hardness and speed have independent effects on the erosion wear rate of 35CrMo steel, and there is no significant coherence.