TiC reinforced AZ91 magnesium matrix composites have been fabricated by a melt in-situ reaction spray deposition. The microstructures of spray-deposited alloys were studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry sliding wear behavior of the alloys was investigated by using a pin-on-disc machine under five loads, namely 10, 20, 30, 40 and 50 N. It has been found that the wear behavior of the alloys was dependent on the TiC content in the microstructure and the applied load. At a lower load (10 N), with increasing TiC content, the wear rate of the alloy was decreased, and the dominant wear mechanism was an oxidative mechanism. At a higher load (50 N), a spray- deposited AZ91/TiC composites exhibited superior wear resistance to the AZ91 magnesium alloy, the dominant wear mechanism was delamination.