TiC/7085 aluminum matrix composites (AMCs) were prepared by the in-situ reaction casting technique. The effects of the nano TiC particles on the microstructure were investigated by light microscopy, X-ray diffractometer, SEM and TEM. The in-situ nano TiC particles showed an obvious effect on the grain refinement of the as-cast microstructure of 7085 aluminum alloy matrix, leading to a microstructural transformation from the coarse dendritic grains to the fine equiaxed grains. The wear resistance of the AMC was further characterized using a NANOVEA micro tribometer. It was found that the wear rate of the AMC decreased and the wear resistance was enhanced due to the additions of the nano TiC particles. The wear mechanism of the TiC/7085 composites was mainly composed of abrasive and adhesive wear.