SiC particle reinforced aluminum metal matrix composites (SiCp/Al) were prepared by powder metallurgy method, and the volume fraction was 5% with size of 3.5 micron and 10 micron. Uniaxial tensile experiments were carried out and the fracture modes were observed. The results demonstrated that the SiC particles in matrix might improve the strength and elastic modulus of the material, but the plastic deformation ability of the material decreased obviously. Based on SEM observation on the microstructure, the boundary cell model (boundary cell finite element method, BCFEM) was established to consider the particle debonded from its surroungding matrix. The particle debonding described by nucleation and growth of voids in matrix，which was investigated using GTN(Gurson-Tvergaard-Needleman) model. The BCFEM model was valid to describe the damage behavior due to the accurate characterization for microstructure of the model.