Abstract: MRH-5A ring block wear tester was used to conduct sliding wear tests on D2 wheel steel and U71Mn rail steel by means of pair-wear tests to study the effect of original structure of D2 wheel steel on its sliding wear performance. The results showed that D2 wheel steel with tempered sorbite (TS) had better wear resistance than D2 wheel steel with lamellar pearlite structure (P)+ proeutectoid ferrite (F). The wear mechanisms of P+F and TS were mainly abrasive wear and adhesive wear, while the wear of P+F was more severe accompanied with the peeling of large white etching layers (WEL). For TS, the plastic deformation layer was thinner, and the ferrite was refined into nanocrystalline. No shear deformation occurred on the granular cementite but dissolution was mainly presented. Because a thicker WEL was unlikely to form and this prevented large peeling, and hence improved the wear resistance.