Abstract: An axisymmetric unit cell model of particle reinforced Al matrix composites was established, and the mechanical behaviors and micro-stress distribution of B₄C particles reinforced Al5083 matrix composites were simulated by finite element method. The results show that the simulation result agrees well with the experimental result. The simulated tensile stress of spheroidicity particle reinforced composites is 485 MPa, while the experimental value is 477 MPa, indicating a relative error as low as 1.7%. Particle shapes have a significant influence on the micro-stress field of composites: the sharp edge of cylindrical particle leads to a stress concentration easily, while the spherical particle results in a relatively uniform stress distribution at the interface. Elastic modulus as well as tensile strength of the composites increase with the increase of volume fraction for B₄C particle in a certain range. In the case of constant particle volume fraction, when the particles with different aspect ratios are aligned along the load direction, the larger the aspect ratio of particles, the higher the elastic modulus and tensile strength of composites.