Abstract: The mechanical properties and fractograph of short mullite fiber reinforced Al-4.5Cu composite fabricated by squeeze cast method were studied in this paper. The experimental results showed that the bending strength and elastic modulus of the composite were improved both with increasing of solidification rate. The fracture surface of the composite showed a character of the brittle cleavage fracture. When the solidification rate was higher, a few mullite fibers were drawn out in certain areas of the fracture surface, and they represented the higher bending strength. In all cases of the solidificating rates studied, a few tough nests on the fracture surface of the composite were also observed.