The particle reinforced aluminum alloy matrix composites, (Al2O3+Al3Zr)p/A359, was fabricated by In-situ reaction in melt A359 and Zr(CO3)2 system. During the fabrication process, a low frequency alternative electromagnetic field was employed to improve the properties of composites by EMS (electromagnetic stirring). The results of dry sliding friction experiments indicate that the wear resistance of composites is better than that of pure matrix alloy. And the wear resistance of composites under a heavy load is further improved by imposing EMS in the fabrication process. By comparison with the composites fabricated without imposing EMS, the critical transition load from mild wear to severe wear of the composites increases from 58.8 N to 78.8 N. The scanning electron microscopy (SEM) analysis of worn-out surfaces indicate that the wear mechanism of pure matrix alloy is adhesive wear and spalling wear, that of composites without EMS in fabrication is mainly abrasion and that of electromagnetic fabricated composites is pure abrasion.