Abstract: The micro-mechanical characteristics of a particulate reinforced magnesium matrix composite was analyzed by FEM simulation.The results showed that such mechanical parameters as Mises equivalent stress,stress spherical tensor,deformation-energy consumption,maximum principal stress and maximum principal strain concentrated markedly in some local areas.The stress concentration might cause local yielding although the loaded force was smaller than the matrix yielding strength.Local interface debonding and matrix cracking are main failure modes in the composite.Moreover,micro-mechanics analysis revealed that the strengthening effect of particulate reinforcements comes mainly from its effect on the stress and strain distribution in matrix,and secondarily from its consumption of the deformation work.