In-situ TiC/Al-4.5Cu composites were made by direct reaction synthesis (DRS) and the effect of TiAl3 phase on the dry wear behavior of the in-situ TiC/Al-4.5Cu composites from 100℃ to 250℃ was studied. The results show that the wear loss of in-situ TiC/Al-4.5Cu increases with the load increasing from 15 to 55N at elevated temperature. The wear loss of the composites containing TiAl3 phase is always larger. There is a critical transition temperature (CTT) of severe wear when the load excesses 35N and the composites with TiAl3 phase possess lower CTT. TiAl3 phase degrades the wear resistance of in-situ TiC/Al-4.5Cu composites.