The slurry erosion behaviors of pseudoelastic TiNi alloy were studied using the liquid/solid impingement system and compared with SUS 630 and 2Cr12NiMo1W1V alloy. The influences of erosion time and angle on erosion resistance of three materials were surveyed. The experimental results show that TiNi alloy has the highest erosion resistance among the three materials and SUS 630 stainless steel is more resistant than 2Cr12NiMoW1V alloy. The KQL-300 indentation tester was used to simulate the impact of particle on material surface during erosion process. The results show that the deformation mode of indention can be pile-up or sink-in and there is a good correlation between erosion resistance of material and its indentation deformation mode. The sink-in deformation mode indicates the higher resistance to erosion, and the pile-up deformation mode implies the lower erosion resistance.