Abstract: Porous alumina particles with an average diameter size of 70 μm were selected as reinforcement.Al₂O_3p/Al composites were prepared by pressureless infiltration in order to investigate the effects of porous alumina particles on the microstructure and mechanical properties of the composites.The results show that the volume fraction, flexural strength and elastic modulus of the porous alumina composites are 30.27vol%, 317.31 MPa and 137.32 GPa, respectively.Finite element analysis shows that the elastic modulus of the composites corresponding to dense alumina particles with the same volume fraction is only 106.58 GPa, using porous alumina can enhance the elastic modulus of the material without increasing the volume fraction of the enhanced phase.