Abstract: Particle reinforced Al-Al₂O₃ composite was made through pressure infiltrating and extruding techniques,the diameters of particles are in the range of 0.15μm to 3,0μm and the particle content is about 30-40%.The structure,fracture feature,strength,hardness and interstice fraction of the composite were examined.We find that the dependence of the logarthmic hardaess on temperature T meets the case of a relaticn of brokctt curve suggested by Goto et al.The turning point of the broken curve,would shift to high temperature if the amount of the reinforcing particles are increased.The fracture is dimple-like.The size of the dimple depends on the size and the amount of the particles,and it also depends on the tension temperature,The strength of this composite is very sensitive to the topology of the particle surface.Based on the phenomeona observed in experiments a fracture mechanism and a possible strengthening way for Al-A1_2O composite are suggested.