Al2O3 short fiber reinforced aluminum matrix composites for high performance piston was prepared by squeezing casting.Tensile strength and elongation of the matrix alloy and composites were analyzed comparatively at di fferent temperature.The results show that the composites exhibit the superiority in tensile strength at high temperature compared to the matrix alloy.Microstructure of the matrix alloy and the composites was observed by the OM（optical microscope）and SEM（scanning electron microscope）.The results show that there exists desirable interface bonding between the matrix alloy and the Al2O3 fiber.The fracture morphology of the composi:es was observed by the SEM.With the increase of temperature

the increase of elongation of the composites can relief the stress aggregation at the interface during tensile process

so interface bonding is enhanced and the reinforced effects are improved.