Three-body abrasive wear behavior of 0.18 wt % C steel was investigated using a ball-cratering tester. Silicon carbide of various sizes was used as an abrasive. Wear test conditions were optimized to ensure three-body abrasive wear preventing two-body abrasive wear during the test. The abrasive was supplied as a slurry form, of which the concentration was 0.75 g/ml. Sliding distance, speed (ball-rotation speed) and normal load were fixed as 50 m, 0.05 m/s, and 0.2 N, respectively. Before the abrasive wear test, 0.18 wt % C steel was heat treated under various conditions to vary its microstructure. Effect of the microstructure as well as the abrasive-particle size on the wear was investigated. It was found that the abrasive wear behavior did not depend on a specific parameter such as hardness; besides, the effect of microstructure and abrasive-particle size was significant in determining the wear of the steel.